A "Smart" Gas Sensing System Based on Integrated Micro Hotplate Arrays and Metal-Oxide Thin-Film Transistors

This thesis addresses challenges associated with traditional metal-oxide semiconductor (MOS) gas sensors and contributes to the evolving field of integrated "smart" gas sensing. The proposed solution involves the development of monolithically integrated gas sensor arrays (GSAs) employing metal-oxide thin-film transistors (MO TFTs). MO TFTs, with notable advantages such as ample mobility, ultra-low leakage current, and compatibility with low-temperature processing, showcase significant potential for MEMS-related integration.

Different from traditional MEMS-CMOS integration, which faces compatibility challenges, silicon migration technology (SiMiT) is employed to create micro-hotplates (MHPs) for GSAs. SiMiT MHPs feature spontaneously suspended structural diaphragms over a sealed cavity, enabling integration with MO TFTs and streamlining fabrication processes. An active-matrix GSA integrated with TFTs is constructed, allowing individual temperature modulation for enhanced gas sensing specificity. The array, utilizing tin dioxide as the sensing material, capitalizes on temperature differences between units to improve specificity for different gas species. Gas-sensing tests for toluene and hydrogen sulfide validate the strategy through principal component analysis (PCA) and software artificial neural networks (ANNs).

Furthermore, dual-gate (DG) MO TFTs find application in neuromorphic computing due to their ultra-low leakage current and dual-gate-dependent current modulation in ANNs. The GSA is combined with a neuromorphic chip based on dual-gate MO TFTs for gas analysis. On-chip ANN training achieves high accuracy in identifying and quantifying acetone and ethanol gases. Drawing inspiration from the olfactory neural system, a hierarchical ANN is constructed for species identification and concentration estimation, with programmed automatic processes for gas analysis. Testing with ethanol, methanol, and ammonia yields accurate identification and quantification. This research contributes to advancing integrated "electronic nose" technology, providing solutions to existing challenges, and implementing an integrated biomimetic artificial olfactory system. The proposed SiMiT-TFT integration offers a promising avenue for manufacturing integrated "smart" systems for diverse applications.

[1] K. G. Krishna, S. Parne, N. Pothukanuri, V. Kathirvelu, S. Gandi, and D. Joshi, “Nanos-tructured metal oxide semiconductor-based gas sensors: A comprehensive review,”Sensors and Actuators A: Physical, vol. 341, p. 113 578, 2022. DOI: https://doi.org/10.1016/j.sna.2022.113578 (cit. on p. 1).
[2] A. Schütze et al., “Highly sensitive and selective voc sensor systems based on semi-conductor gas sensors: How to?” Environments, vol. 4, no. 1, 2017. DOI: 10.3390/environments4010020 (cit. on p. 1).
[3] S. Xue, S. Cao, Z. Huang, D. Yang, and G. Zhang, “Improving gas-sensing performancebased on mos nanomaterials: A review,” Materials, vol. 14, no. 15, 2021. DOI: 10 .3390/ma14154263 (cit. on p. 1).
[4] J. Zhang, Z. Qin, D. Zeng, and C. Xie, “Metal-oxide-semiconductor based gas sensors:Screening, preparation, and integration,” Phys. Chem. Chem. Phys., vol. 19, pp. 6313–6329, 2017. DOI: 10.1039/C6CP07799D (cit. on p. 1).
[5] S. Sharma and M. Madou, “A new approach to gas sensing with nanotechnology,” Phil.Trans. R. Soc. A, vol. 370, pp. 2448–2473, 2012. DOI: 10. 1098 / rsta . 2011 .0506 (cit. on p. 1).
[6] N. A. Isaac, I. Pikaar, and G. Biskos, “Metal oxide semiconducting nanomaterials forair quality gas sensors: Operating principles, performance, and synthesis techniques,”Microchimica Acta, vol. 189, no. 5, p. 196, 2022. DOI: 10.1007/s00604-022-05254-0 (cit. on p. 1).
[7] R. De Fazio, A.-R. Al-Hinnawi, M. De Vittorio, and P. Visconti, “An energy-autonomoussmart shirt employing wearable sensors for users’ safety and protection in hazardousworkplaces,” Applied Sciences, vol. 12, no. 6, 2022. DOI: 10.3390/app12062926(cit. on p. 1).
[8] S. Das and M. Pal, “Review—non-invasive monitoring of human health by exhaledbreath analysis: A comprehensive review,” Journal of The Electrochemical Society,vol. 167, no. 3, p. 037 562, Feb. 2020. DOI: 10 . 1149 / 1945 - 7111 / ab67a6(cit. on p. 1).94
[9] J. B. A. Gomes, J. J. P. C. Rodrigues, R. A. L. Rab￿lo, N. Kumar, and S. Kozlov, “Iot-enabled gas sensors: Technologies, applications, and opportunities,” Journal of Sensorand Actuator Networks, vol. 8, no. 4, 2019. DOI: 10.3390/jsan8040057 (cit. onp. 1).
[10] S. Kumar, Y. Lalitha Kameswari, and S. Koteswara Rao, “Smart grid management forsmart city infrastructure using wearable sensors,” in Data Analytics for Smart GridsApplications—A Key to Smart City Development, D. Kumar Sharma, R. Sharma, G.Jeon, and R. Kumar, Eds. Cham: Springer Nature Switzerland, 2023, pp. 39–63. DOI:10.1007/978-3-031-46092-0_4 (cit. on p. 1).
[11] D. Y. Nadargi et al., “Gas sensors and factors influencing sensing mechanism with aspecial focus on MOS sensors,” Journal of Materials Science, vol. 58, no. 2, pp. 559–582, Jan. 2023. DOI: 10.1007/s10853-022-08072-0 (cit. on p. 1).
[12] S. Zampolli et al., “An electronic nose based on solid state sensor arrays for low-cost indoor air quality monitoring applications,” Sensors and Actuators B: Chemical,vol. 101, no. 1, pp. 39–46, 2004. DOI: https://doi.org/10.1016/j.snb.2004.02.024 (cit. on p. 1).
[13] J. W. Gardner, P. K. Guha, F. Udrea, and J. A. Covington, “Cmos interfacing forintegrated gas sensors: A review,” IEEE Sensors Journal, vol. 10, no. 12, pp. 1833–1848, 2010. DOI: 10.1109/JSEN.2010.2046409 (cit. on pp. 1, 2).
[14] P. C. Chan et al., “An integrated gas sensor technology using surface micro-machining,”Sensors and Actuators B: Chemical, vol. 82, no. 2, pp. 277–283, 2002. DOI: https://doi.org/10.1016/S0925-4005(01)01064-4 (cit. on pp. 2, 25).
[15] L. Filipovic and A. Lahlalia, “Review——system-on-chip smo gas sensor integration inadvanced cmos technology,” Journal of The Electrochemical Society, vol. 165, no. 16,B862, Dec. 2018. DOI: 10.1149/2.0731816jes (cit. on p. 2).
[16] T. P. Raptis, A. Passarella, and M. Conti, “Data management in industry 4.0: State ofthe art and open challenges,” IEEE Access, vol. 7, pp. 97 052–97 093, 2019. DOI: 10.1109/ACCESS.2019.2929296 (cit. on p. 2).
[17] J. Gutiérrez and M. Horrillo, “Advances in artificial olfaction: Sensors and applications,”Talanta, vol. 124, pp. 95–105, 2014. DOI: https://doi.org/10.1016/j.talanta.2014.02.016 (cit. on p. 6).95
[18] G. Korotcenkov, “Handbook of gas sensor materials,” Conventional approaches, vol. 1,2013 (cit. on pp. 6, 12).
[19] M. V. Nikolic, V. Milovanovic, Z. Z. Vasiljevic, and Z. Stamenkovic, “Semiconductorgas sensors: Materials, technology, design, and application,” Sensors, vol. 20, no. 22,2020. DOI: 10.3390/s20226694 (cit. on p. 6).
[20] S. Bhattacharya, S. Sridevi, and R. Pitchiah, “Indoor air quality monitoring usingwireless sensor network,” in 2012 Sixth International Conference on Sensing Technology(ICST), 2012, pp. 422–427. DOI: 10.1109/ICSensT.2012.6461713 (cit. onp. 6).
[21] J. Lee et al., “High-performance gas sensor array for indoor air quality monitoring: Therole of au nanoparticles on wo 3, sno 2, and nio-based gas sensors,” Journal of MaterialsChemistry A, vol. 9, no. 2, pp. 1159–1167, 2021 (cit. on p. 6).
[22] M. B. Marinov, I. Topalov, E. Gieva, and G. Nikolov, “Air quality monitoring in urbanenvironments,” in 2016 39th International Spring Seminar on Electronics Technology(ISSE), 2016, pp. 443–448. DOI: 10.1109/ISSE.2016.7563237 (cit. on p. 6).
[23] A. Kumar et al., “Application of gas monitoring sensors in underground coal minesand hazardous areas,” International Journal of Computer Technology and ElectronicsEngineering, vol. 3, no. 3, pp. 9–23, 2013 (cit. on p. 6).
[24] V. Ramya and B. Palaniappan, “Embedded system for hazardous gas detection andalerting,” International Journal of Distributed and Parallel Systems (IJDPS), vol. 3,no. 3, pp. 287–300, 2012 (cit. on p. 6).
[25] M. F. R. Al-Okby, S. Neubert, T. Roddelkopf, and K. Thurow, “Mobile detectionand alarming systems for hazardous gases and volatile chemicals in laboratories andindustrial locations,” Sensors, vol. 21, no. 23, p. 8128, 2021 (cit. on p. 6).
[26] Z. Zhai, X. Zhang, X. Hao, B. Niu, and C. Li, “Metal–organic frameworks materials forcapacitive gas sensors,” Advanced Materials Technologies, vol. 6, no. 10, p. 2 100 127,2021 (cit. on p. 6).
[27] S. Matindoust, M. Baghaei-Nejad, M. H. S. Abadi, Z. Zou, and L.-R. Zheng, “Foodquality and safety monitoring using gas sensor array in intelligent packaging,” SensorReview, vol. 36, no. 2, pp. 169–183, 2016 (cit. on p. 6).96
[28] L. R. Khot, S. Panigrahi, and D. Lin, “Development and evaluation of piezoelectric-polymer thin film sensors for low concentration detection of volatile organic compoundsrelated to food safety applications,” Sensors and Actuators B: Chemical, vol. 153, no. 1,pp. 1–10, 2011 (cit. on p. 6).
[29] X. Meng, S. Kim, P. Puligundla, and S. Ko, “Carbon dioxide and oxygen gas sensors-possible application for monitoring quality, freshness, and safety of agricultural and foodproducts with emphasis on importance of analytical signals and their transformation,”Journal of the Korean Society for Applied Biological Chemistry, vol. 57, pp. 723–733,2014 (cit. on p. 6).
[30] D. Krichen, W. Abdallah, N. Boudriga, and A. Bagula, “A public safety wireless sensornetwork: A visible light communication based approach,” in e-Infrastructure and e-Services: 7th International Conference, AFRICOMM 2015, Cotonou, Benin, December15-16, 2015, Revised Selected Papers 7, Springer, 2016, pp. 203–214 (cit. on p. 7).
[31] R. A. Potyrailo et al., “Wireless sensors and sensor networks for homeland securityapplications,” TrAC Trends in Analytical Chemistry, vol. 40, pp. 133–145, 2012 (cit. onp. 7).
[32] F. K. F. Cheong, K. Jung, S. Moura, and W. L. W. Wong, “Airsims: A simulator andexecutor for a safer airport environment,” 2005 (cit. on p. 7).
[33] G. Hunter et al., “A hazardous gas detection system for aerospace and commercialapplications,” in 34th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit,1998, p. 3614 (cit. on p. 7).
[34] G. Hunter et al., “The development of micro/nano chemical sensor systems for aerospaceapplications,” in Micro-and Nanotechnology Sensors, Systems, and Applications II,SPIE, vol. 7679, 2010, pp. 215–226 (cit. on p. 7).
[35] S. Bhattacharya, A. K. Agarwal, O. Prakash, and S. Singh, Sensors for automotive andaerospace applications. Springer, 2018 (cit. on p. 7).
[36] X. Chen, M. Leishman, D. Bagnall, and N. Nasiri, “Nanostructured gas sensors: Fromair quality and environmental monitoring to healthcare and medical applications,”Nanomaterials, vol. 11, no. 8, p. 1927, 2021 (cit. on p. 7).
[37] W. SHIN, T. ITOH, and N. IZU, “Health care application of gas sensors—medicaldevices of breath analysis—,” Synthesiology English edition, vol. 8, no. 4, pp. 211–219,2015 (cit. on p. 7).97
[38] A. Kaushik, R. Kumar, R. D. Jayant, and M. Nair, “Nanostructured gas sensors for healthcare: An overview,” Journal of personalized nanomedicine, vol. 1, no. 1, p. 10, 2015 (cit.on p. 7).
[39] M. A. Ramírez-Moreno et al., “Sensors for sustainable smart cities: A review,” AppliedSciences, vol. 11, no. 17, p. 8198, 2021 (cit. on p. 7).
[40] H. Omidvarborna, P. Kumar, J. Hayward, M. Gupta, and E. G. S. Nascimento, “Low-cost air quality sensing towards smart homes,” Atmosphere, vol. 12, no. 4, p. 453, 2021(cit. on p. 7).
[41] A. Belghith and M. Obaidat, “Wireless sensor networks applications to smart homes andcities,” in Smart cities and homes, Elsevier, 2016, pp. 17–40 (cit. on p. 7).
[42] S. A. Hooker et al., “Nanotechnology advantages applied to gas sensor development,” inThe nanoparticles 2002 conference proceedings, Business Communications Co., Inc.,2002, pp. 1–7 (cit. on p. 8).
[43] G. Korotcenkov, “Metal oxides for solid-state gas sensors: What determines our choice?”Materials Science and Engineering: B, vol. 139, no. 1, pp. 1–23, 2007. DOI: https://doi.org/10.1016/j.mseb.2007.01.044 (cit. on p. 8).
[44] C.-H. Han, D.-W. Hong, S.-D. Han, J. Gwak, and K. C. Singh, “Catalytic combustiontype hydrogen gas sensor using tio2 and uv-led,” Sensors and Actuators B: Chemical,vol. 125, no. 1, pp. 224–228, 2007 (cit. on p. 8).
[45] E. Brauns, E. Morsbach, S. Kunz, M. Bäumer, and W. Lang, “A fast and sensitivecatalytic gas sensors for hydrogen detection based on stabilized nanoparticles as catalyticlayer,” Sensors and Actuators B: Chemical, vol. 193, pp. 895–903, 2014 (cit. on p. 8).
[46] M. Raninec, “Overcoming the technical challenges of electrochemical gas sensing,”Norwood, MA, USA, Analog Devices, Technical Article, pp. 1–5, 2019 (cit. on p. 8).
[47] R. Paul, B. Das, and R. Ghosh, “Novel approaches towards design of metal oxide basedhetero-structures for room temperature gas sensor and its sensing mechanism: A recentprogress,” Journal of Alloys and Compounds, vol. 941, p. 168 943, 2023. DOI: https://doi.org/10.1016/j.jallcom.2023.168943 (cit. on p. 8).
[48] E. L. W. Gardner, J. W. Gardner, and F. Udrea, “Micromachined thermal gas sensors—areview,” Sensors, vol. 23, no. 2, 2023. DOI: 10.3390/s23020681 (cit. on p. 8).
[49] J. Hodgkinson and R. P. Tatam, “Optical gas sensing: A review,” Measurement scienceand technology, vol. 24, no. 1, p. 012 004, 2012 (cit. on p. 8).98
[50] D. Zhang, Z. Yang, S. Yu, Q. Mi, and Q. Pan, “Diversiform metal oxide-based hybridnanostructures for gas sensing with versatile prospects,” Coordination Chemistry Re-views, vol. 413, p. 213 272, 2020. DOI: https://doi.org/10.1016/j.ccr.2020.213272 (cit. on p. 8).
[51] S. Xue, S. Cao, Z. Huang, D. Yang, and G. Zhang, “Improving gas-sensing performancebased on mos nanomaterials: A review,” Materials (Basel), vol. 14, no. 15, p. 4263, Jul.2021. DOI: 10.3390/ma14154263 (cit. on p. 8).
[52] N. Goel, K. Kunal, A. Kushwaha, and M. Kumar, “Metal oxide semiconductors for gassensing,” Engineering Reports, vol. 5, no. 6, e12604, 2023 (cit. on p. 9).
[53] H. Tai, Z. Duan, Y. Wang, S. Wang, and Y. Jiang, “Based sensors for gas, humidity,and strain detections: A review,” ACS applied materials and interfaces, vol. 12, no. 28,pp. 31 037–31 053, 2020 (cit. on p. 9).
[54] G. H. Jain, “Mos gas sensors: What determines our choice?” In 2011 Fifth InternationalConference on Sensing Technology, IEEE, 2011, pp. 66–72 (cit. on p. 9).
[55] S. Das, S. Mojumder, D. Saha, and M. Pal, “Influence of major parameters on the sensingmechanism of semiconductor metal oxide based chemiresistive gas sensors: A reviewfocused on personalized healthcare,” Sensors and Actuators B: Chemical, vol. 352,p. 131 066, 2022. DOI: https : / / doi . org / 10 . 1016 / j . snb . 2021 .131066 (cit. on p. 9).
[56] I. A. Alagdal and A. R. West, “Oxygen non-stoichiometry, conductivity and gas sensorresponse of sno 2 pellets,” Journal of Materials Chemistry A, vol. 3, no. 46, pp. 23 213–23 219, 2015 (cit. on p. 9).
[57] S. Nandy, U. Maiti, C. Ghosh, and K. Chattopadhyay, “Enhanced p-type conductivityand band gap narrowing in heavily al doped nio thin films deposited by rf magnetronsputtering,” Journal of Physics: Condensed Matter, vol. 21, no. 11, p. 115 804, 2009(cit. on p. 9).
[58] A. Rothschild and Y. Komem, “Numerical computation of chemisorption isotherms fordevice modeling of semiconductor gas sensors,” Sensors and Actuators B: Chemical,vol. 93, no. 1, pp. 362–369, 2003, Proceedings of the Ninth International Meeting onChemical Sensors. DOI: https://doi.org/10.1016/S0925-4005(03)00212-0 (cit. on p. 9).99
[59] H.-J. Kim and J.-H. Lee, “Highly sensitive and selective gas sensors using p-type oxidesemiconductors: Overview,” Sensors and Actuators B: Chemical, vol. 192, pp. 607–627,2014. DOI: https://doi.org/10.1016/j.snb.2013.11.005 (cit. onp. 11).
[60] H.-J. Kim and J.-H. Lee, “Highly sensitive and selective gas sensors using p-type oxidesemiconductors: Overview,” Sensors and Actuators B: Chemical, vol. 192, pp. 607–627,2014 (cit. on p. 12).
[61] Y. Kong et al., “Sno2 nanostructured materials used as gas sensors for the detectionof hazardous and flammable gases: A review,” Nano Materials Science, vol. 4, no. 4,pp. 339–350, 2022. DOI: https://doi.org/10.1016/j.nanoms.2021.05.006 (cit. on p. 12).
[62] M. Ma, X. Yang, X. Ying, C. Shi, Z. Jia, and B. Jia, “Applications of gas sensing infood quality detection: A review,” Foods, vol. 12, no. 21, 2023. DOI: 10 . 3390 /foods12213966 (cit. on p. 12).
[63] M. C. Latino and G. Neri, “Chemoresistive metal oxide gas sensor: Working principlesand applications,” Atti della Accademia Peloritana dei Pericolanti-Classe di ScienzeFisiche, Matematiche e Naturali, vol. 99, no. S1, p. 41, 2021 (cit. on p. 13).
[64] T. Dai et al., “Generic approach to boost the sensitivity of metal oxide sensors bydecoupling the surface charge exchange and resistance reading process,” ACS AppliedMaterials and Interfaces, vol. 12, no. 33, pp. 37 295–37 304, 2020, PMID: 32700520.DOI: 10.1021/acsami.0c07626 (cit. on p. 13).
[65] G. G. Mandayo, “Gas detection by semiconductor ceramics: Tin oxide as improvedsensing material,” Sensor Letters, vol. 5, no. 2, pp. 341–360, 2007 (cit. on p. 13).
[66] A. A. Tomchenko, “Printed chemical sensors: From screen-printing to microprinting∗,”Encycl. Sens, vol. 10, pp. 279–290, 2006 (cit. on pp. 13, 14).
[67] B. Tang, Y. Shi, J. Li, J. Tang, and Q. Feng, “Design, simulation, and fabrication ofmultilayer al2o3 ceramic micro-hotplates for high temperature gas sensors,” Sensors,vol. 22, no. 18, p. 6778, 2022 (cit. on pp. 13, 14).
[68] V. Baloria, C. S. Prajapati, N. Bhat, and G. Gupta, “Chemiresistors and their microfabri-cation,” Functional Nanomaterials: Advances in Gas Sensing Technologies, pp. 71–94,2020 (cit. on p. 13).100
[69] J. Zhu et al., “Development trends and perspectives of future sensors and mems/nems,”Micromachines, vol. 11, no. 1, p. 7, 2019 (cit. on p. 14).
[70] A. S. Algamili et al., “A review of actuation and sensing mechanisms in mems-basedsensor devices,” Nanoscale research letters, vol. 16, pp. 1–21, 2021 (cit. on p. 14).
[71] Z. Yuan, F. Yang, F. Meng, K. Zuo, and J. Li, “Research of low-power mems-based microhotplates gas sensor: A review,” IEEE Sensors Journal, vol. 21, no. 17, pp. 18 368–18 380, 2021 (cit. on p. 14).
[72] H. Liu, L. Zhang, K. H. H. Li, and O. K. Tan, “Microhotplates for metal oxidesemiconductor gas sensor applications—towards the cmos-mems monolithic approach,”Micromachines, vol. 9, no. 11, p. 557, 2018 (cit. on p. 14).
[73] N. Yamazoe and K. Shimanoe, “Roles of shape and size of component crystals insemiconductor gas sensors: Ii. response to,” Journal of The Electrochemical Society,vol. 155, no. 4, J93, 2008. DOI: 10.1149/1.2832662 (cit. on p. 15).
[74] Z. Yuan, F. Yang, F. Meng, K. Zuo, and J. Li, “Research of low-power mems-based microhotplates gas sensor: A review,” IEEE Sensors Journal, vol. 21, no. 17, pp. 18 368–18 380, 2021. DOI: 10.1109/JSEN.2021.3088440 (cit. on p. 15).
[75] H. Zhao, Y. Wang, and Y. Zhou, “Accelerating the gas-solid interactions for conducto-metric gas sensors: Impacting factors and improvement strategies,” Materials, vol. 16,no. 8, 2023. DOI: 10.3390/ma16083249 (cit. on p. 15).
[76] Y. Wang and Y. Zhou, “Recent progress on anti-humidity strategies of chemiresistive gassensors,” Materials (Basel), vol. 15, no. 24, p. 8728, Dec. 7, 2022. DOI: 10.3390/ma15248728 (cit. on p. 15).
[77] G. Müller and G. Sberveglieri, “Origin of baseline drift in metal oxide gas sensors:Effects of bulk equilibration,” Chemosensors, vol. 10, no. 5, 2022. DOI: 10.3390/chemosensors10050171 (cit. on p. 15).
[78] K. J. Albert et al., “Cross-reactive chemical sensor arrays,” Chemical Reviews, vol. 100,no. 7, pp. 2595–2626, 2000. DOI: 10.1021/cr980102w (cit. on p. 16).
[79] Z. Chen, Z. Chen, Z. Song, W. Ye, and Z. Fan, “Smart gas sensor arrays powered byartificial intelligence,” Journal of Semiconductors, vol. 40, no. 11, p. 111 601, Nov. 2019.DOI: 10.1088/1674-4926/40/11/111601 (cit. on p. 16).101Meeting 1998. Technical Digest (Cat. No.98CH36217), 1998, pp. 137–140. DOI: 10.1109/IEDM.1998.746298 (cit. on p. 27).
[80] M. Modak and S. Jagtap, “Low temperature operated highly sensitive, selective andstable no2 gas sensors using n-doped sno2-rgo nanohybrids,” Ceramics International,vol. 48, no. 14, pp. 19 978–19 989, 2022. DOI: https://doi.org/10.1016/j.ceramint.2022.03.273 (cit. on p. 16).
[81] M. Weber et al., “Highly efficient hydrogen sensors based on pd nanoparticles supportedon boron nitride coated zno nanowires,” Journal of Materials Chemistry A, vol. 7,pp. 8107–8116, 2019, † Communication. DOI: 10.1039/C9TA00788A (cit. onp. 16).
[82] Y.-L. Pan and W.-C. Liu, “Study of a platinum (pt) nanoparticle (np)/vanadium pentoxide(v2o5) thin film-based ammonia gas sensor,” IEEE Transactions on Electron Devices,vol. 67, no. 5, pp. 2126–2132, 2020. DOI: 10.1109/TED.2020.2981113 (cit. onp. 16).
[83] Y.-F. Sun et al., “Metal oxide nanostructures and their gas sensing properties: A review,”Sensors, vol. 12, no. 3, pp. 2610–2631, 2012. DOI: 10.3390/s120302610 (cit. onp. 17).
[84] F. Meng et al., “Mos2-templated porous hollow moo3 microspheres for highly selectiveammonia sensing via a lewis acid-base interaction,” IEEE Transactions on IndustrialElectronics, vol. 69, no. 1, pp. 960–970, Jan. 2022. DOI: 10.1109/TIE.2021.3053902 (cit. on p. 17).
[85] X. Wu et al., “Mof-smo hybrids as a h2s sensor with superior sensitivity and selectivity,”Sensors and Actuators B: Chemical, vol. 292, pp. 32–39, 2019. DOI: https://doi.org/10.1016/j.snb.2019.04.076 (cit. on p. 17).
[86] L. Song et al., “One-step electrospun sno2/mox heterostructured nanomaterials forhighly selective gas sensor array integration,” Sensors and Actuators B: Chemical,vol. 283, pp. 793–801, 2019. DOI: https://doi.org/10.1016/j.snb.2018.12.097 (cit. on p. 17).
[87] L. Xu et al., “Nio@zno heterostructured nanotubes: Coelectrospinning fabrication, characterization, and highly enhanced gas sensing properties,” Inorganic Chemistry, vol. 51,no. 14, pp. 7733–7740, 2012, PMID: 22747254. DOI: 10.1021/ic300749a (cit.on p. 17).102
[88] K. D. Mitzner, J. Sternhagen, and D. W. Galipeau, “Development of a micromachinedhazardous gas sensor array,” Sensors and Actuators B: Chemical, vol. 93, no. 1, pp. 92–99, 2003, Proceedings of the Ninth International Meeting on Chemical Sensors. DOI:https://doi.org/10.1016/S0925- 4005(03)00244- 2 (cit. onp. 18).
[89] A. Srivastava, “Detection of volatile organic compounds (vocs) using sno2 gas-sensorarray and artificial neural network,” Sensors and Actuators B: Chemical, vol. 96, no. 1,pp. 24–37, 2003. DOI: https://doi.org/10.1016/S0925-4005(03)00477-5 (cit. on p. 18).
[90] C. S. Prajapati, R. Soman, S. B. Rudraswamy, M. Nayak, and N. Bhat, “Single chip gassensor array for air quality monitoring,” Journal of Microelectromechanical Systems,vol. 26, no. 2, pp. 433–439, 2017. DOI: 10.1109/JMEMS.2017.2657788 (cit.on p. 18).
[91] Y. Zhang, J. Zhao, T. Du, Z. Zhu, J. Zhang, and Q. Liu, “A gas sensor array for thesimultaneous detection of multiple vocs,” Scientific Reports, vol. 7, no. 1, p. 1960, 2017.DOI: 10.1038/s41598-017-02150-z (cit. on pp. 18, 20).
[92] A. T. Güntner, V. Koren, K. Chikkadi, M. Righettoni, and S. E. Pratsinis, “E-nose sensingof low-ppb formaldehyde in gas mixtures at high relative humidity for breath screeningof lung cancer?” ACS Sensors, vol. 1, no. 5, pp. 528–535, 2016. DOI: 10 . 1021 /acssensors.6b00008 (cit. on pp. 18, 20).
[93] Y. Mo, Y. Okawa, M. Tajima, T. Nakai, N. Yoshiike, and K. Natukawa, “Micro-machinedgas sensor array based on metal film micro-heater,” Sensors and Actuators B: Chemical,vol. 79, no. 2, pp. 175–181, 2001. DOI: https://doi.org/10.1016/S0925-4005(01)00871-1 (cit. on pp. 19, 20).
[94] M. Afridi et al., “A monolithic cmos microhotplate-based gas sensor system,” IEEESensors Journal, vol. 2, no. 6, pp. 644–655, 2002. DOI: 10.1109/JSEN.2002.807780 (cit. on pp. 19, 20, 41).
[95] S. Helal, H. Sarieddeen, H. Dahrouj, T. Y. Al-Naffouri, and M.-S. Alouini, “Signalprocessing and machine learning techniques for terahertz sensing: An overview,” IEEESignal Processing Magazine, vol. 39, no. 5, pp. 42–62, 2022. DOI: 10.1109/MSP.2022.3183808 (cit. on p. 21).103
[96] S. Guney and A. Atasoy, “Multiclass classification of n-butanol concentrations with knearest neighbor algorithm and support vector machine in an electronic nose,” Sensorsand Actuators B: Chemical, vol. 166-167, pp. 721–725, 2012. DOI: https://doi.org/10.1016/j.snb.2012.03.047 (cit. on p. 21).
[97] A. Szczurek, M. Maciejewska, B. Bffk, J. Wilk, J. Wilde, and M. Siuda, “Gas sensorarray and classifiers as a means of varroosis detection,” Sensors, vol. 20, no. 1, 2020.DOI: 10.3390/s20010117 (cit. on p. 21).
[98] S. Feng et al., “Review on smart gas sensing technology,” Sensors, vol. 19, no. 17, 2019.DOI: 10.3390/s19173760 (cit. on p. 21).
[99] H.-K. Hong, C. H. Kwon, S.-R. Kim, D. H. Yun, K. Lee, and Y. K. Sung, “Portableelectronic nose system with gas sensor array and artificial neural network,” Sensors andActuators B: Chemical, vol. 66, no. 1, pp. 49–52, 2000. DOI: https://doi.org/10.1016/S0925-4005(99)00460-8 (cit. on p. 21).
[100] M. Kang et al., “High accuracy real-time multi-gas identification by a batch-uniformgas sensor array and deep learning algorithm,” ACS Sensors, vol. 7, no. 2, pp. 430–440,2022, doi: 10.1021/acssensors.1c01204. DOI: 10.1021/acssensors.1c01204(cit. on p. 21).
[101] Z. Zhang, X. Liu, H. Zhou, S. Xu, and C. Lee, “Advances in machine-learning enhancednanosensors: From cloud artificial intelligence toward future edge computing at chiplevel,” Small Structures, p. 2 300 325, 2023 (cit. on p. 21).
[102] E. Covi et al., “Adaptive extreme edge computing for wearable devices,” Frontiers inNeuroscience, vol. 15, p. 611 300, 2021 (cit. on p. 21).
[103] D. Liu, H. Yu, and Y. Chai, “Low-power computing with neuromorphic engineering,”Advanced Intelligent Systems, vol. 3, no. 2, p. 2 000 150, 2021 (cit. on p. 21).
[104] G. Chakma, N. D. Skuda, C. D. Schuman, J. S. Plank, M. E. Dean, and G. S.Rose, “Energy and area efficiency in neuromorphic computing for resource constraineddevices,” in Proceedings of the 2018 on Great Lakes Symposium on VLSI, 2018, pp. 379–383 (cit. on p. 21).
[105] S. Hamdan, M. Ayyash, and S. Almajali, “Edge-computing architectures for internet ofthings applications: A survey,” Sensors, vol. 20, no. 22, p. 6441, 2020 (cit. on p. 21).104
[106] M. I. A. Asri, M. N. Hasan, M. R. A. Fuaad, Y. M. Yunos, and M. S. M. Ali, “Memsgas sensors: A review,” IEEE Sensors Journal, vol. 21, no. 17, pp. 18 381–18 397, 2021.DOI: 10.1109/JSEN.2021.3091854 (cit. on p. 23).
[107] P. Bhattacharyya, “Technological journey towards reliable microheater development formems gas sensors: A review,” IEEE Transactions on Device and Materials Reliability,vol. 14, no. 2, pp. 589–599, 2014. DOI: 10.1109/TDMR.2014.2311801 (cit. onp. 23).
[108] M. Prasad and P. S. Dutta, “Development of micro-hotplate and its reliability for gassensing applications,” Applied Physics A, vol. 124, no. 11, p. 788, 2018. DOI: 10 .1007/s00339-018-2210-4 (cit. on p. 24).
[109] M. Prasad and V. K. Khanna, “A low-power, micromachined, double spiral hotplate formems gas sensors,” Microsystem Technologies, vol. 21, no. 10, pp. 2123–2131, 2015.DOI: 10.1007/s00542-014-2393-3 (cit. on p. 24).
[110] T. Iwata, W. P. C. Soo, K. Matsuda, K. Takahashi, M. Ishida, and K. Sawada, “Design,fabrication, and characterization of bridge-type micro-hotplates with an su-8 supportinglayer for a smart gas sensing system,” Journal of Micromechanics and Microengineering,vol. 27, no. 2, p. 024 003, Jan. 11, 2017, Special issue on Transducers and Micro-NanoTechnology. DOI: 10.1088/1361-6439/aa556b (cit. on pp. 24, 25).
[111] G. Kovacs, N. Maluf, and K. Petersen, “Bulk micromachining of silicon,” Proceedingsof the IEEE, vol. 86, no. 8, pp. 1536–1551, 1998. DOI: 10.1109/5.704259 (cit. onp. 24).
[112] S. Semancik et al., “Microhotplate platforms for chemical sensor research,” Sensors andActuators B: Chemical, vol. 77, no. 1, pp. 579–591, 2001, Proceeding of the EighthInternational Meeting on Chemical Sensors IMCS-8 - Part 2. DOI: https://doi.org/10.1016/S0925-4005(01)00695-5 (cit. on p. 24).
[113] C. Dffcsff et al., “Porous silicon bulk micromachining for thermally isolated membraneformation,” Sensors and Actuators A: Physical, vol. 60, no. 1, pp. 235–239, 1997,Proceedings of Eurosensors X. DOI: https://doi.org/10.1016/S0924-4247(97)01384-8 (cit. on p. 24).
[114] S. Franssila, Introduction to Microfabrication. John Wiley and Sons, 2010 (cit. on p. 25).105
[115] R. T. Howe, “Surface micromachining for microsensors and microactuators,” Journalof Vacuum Science and Technology B: Microelectronics Processing and Phenomena,vol. 6, no. 6, pp. 1809–1813, 1988 (cit. on p. 25).
[116] C. Linder, L. Paratte, M.-A. Gretillat, V. P. Jaecklin, and N. F. de Rooij, “Surfacemicromachining,” Journal of Micromechanics and Microengineering, vol. 2, no. 3,p. 122, 1992. DOI: 10.1088/0960-1317/2/3/003 (cit. on p. 25).
[117] J. Bustillo, R. Howe, and R. Muller, “Surface micromachining for microelectromechanical systems,” Proceedings of the IEEE, vol. 86, no. 8, pp. 1552–1574, 1998. DOI: 10.1109/5.704260 (cit. on p. 25).
[118] B. Guo, A. Bermak, P. C. H. Chan, and G.-Z. Yan, “An integrated surface micromachinedconvex microhotplate structure for tin oxide gas sensor array,” IEEE Sensors Journal,vol. 7, no. 12, pp. 1720–1726, 2007. DOI: 10.1109/JSEN.2007.908919 (cit. onp. 25).
[119] H. Liu, L. Zhang, K. H. H. Li, and O. K. Tan, “Microhotplates for metal oxidesemiconductor gas sensor applications—towards the cmos-mems monolithic approach,”Micromachines, vol. 9, no. 11, 2018. DOI: 10.3390/mi9110557 (cit. on p. 25).
[120] K. Wise, “Integrated sensors: Interfacing electronics to a non-electronic world,” Sensorsand Actuators, vol. 2, pp. 229–237, 1981. DOI: https://doi.org/10.1016/0250-6874(81)80043-1 (cit. on p. 25).
[121] C. Hagleitner et al., “Smart single-chip gas sensor microsystem,” Nature, vol. 414,no. 6861, pp. 293–296, 2001 (cit. on p. 25).
[122] M. Graf et al., “Cmos monolithic metal-oxide sensor system comprising a microhotplateand associated circuitry,” IEEE Sensors Journal, vol. 4, no. 1, pp. 9–16, 2004 (cit. onp. 25).
[123] L. Filipovic and S. Selberherr, “Integration of gas sensors with cmos technology,” in2020 4th IEEE Electron Devices Technology and Manufacturing Conference (EDTM),2020, pp. 1–4. DOI: 10.1109/EDTM47692.2020.9117828 (cit. on p. 25).
[124] D. T. Thu et al., “A miniaturized cmos-mems amperometric gas sensor for rapid ethanoldetection,” IEEE Sensors Journal, vol. 23, no. 8, pp. 8128–8137, 2023. DOI: 10 .1109/JSEN.2023.3254881 (cit. on p. 25).
[125] Z.-H. Liu et al., “A miniaturized cmos-mems amperometric gas sensor for rapid ethanoldetection,” IEEE Sensors Journal, 2023 (cit. on p. 25).106
[126] A. Krayden, D. Shlenkevitch, T. Blank, S. Stolyarova, and Y. Nemirovsky, “Selectivesensing of mixtures of gases with cmos-soi-mems sensor dubbed gmos,” Micromachines, vol. 14, no. 2, 2023. DOI: 10.3390/mi14020390 (cit. on p. 25).
[127] H. Baltes, O. Paul, and O. Brand, “Micromachined thermally based cmos microsensors,”Proceedings of the IEEE, vol. 86, no. 8, pp. 1660–1678, 1998. DOI: 10.1109/5.704271 (cit. on p. 26).
[128] M. Graf, D. Barrettino, K.-U. Kirstein, and A. Hierlemann, “Cmos microhotplate sensorsystem for operating temperatures up to 500°c,” Sensors and Actuators B: Chemical,vol. 117, no. 2, pp. 346–352, 2006, Transducers ’05. DOI: https://doi.org/10.1016/j.snb.2005.11.012 (cit. on p. 26).
[129] J. Smith, S. Montague, J. Sniegowski, J. Murray, and P. McWhorter, “Embeddedmicromechanical devices for the monolithic integration of mems with cmos,” in Proceedings of International Electron Devices Meeting, 1995, pp. 609–612. DOI: 10 .1109/IEDM.1995.499295 (cit. on p. 26).
[130] A. Roy, B. Q. Ta, M. Azadmehr, and K. E. Aasmundtveit, “Post-cmos processing challenges and design developments of cmos-mems microheaters for local cnt synthesis,”Microsystems and Nanoengineering, vol. 9, no. 1, p. 136, Nov. 2023. DOI: 10.1038/s41378-023-00598-w (cit. on p. 26).
[131] Y.-C. Cheng, C.-L. Dai, C.-Y. Lee, P.-H. Chen, and P.-Z. Chang, “A mems micromirrorfabricated using cmos post-process,” Sensors and Actuators A: Physical, vol. 120, no. 2,pp. 573–581, 2005. DOI: https://doi.org/10.1016/j.sna.2005.02.009 (cit. on p. 26).
[132] J. O. Dennis, F. Ahmad, and H. Khir, “Cmos compatible bulk micromachining,”Advances in micro/nano electromechanical systems and fabrication technologies, p. 226,2013 (cit. on p. 26).
[133] L. Sun, L. Qian, P. Hong, G. Yan, and Z. Yang, “Post cmos integration of high aspectratio soi mems devices,” in 2011 6th IEEE International Conference on Nano/MicroEngineered and Molecular Systems, 2011, pp. 166–169. DOI: 10 . 1109 / NEMS .2011.6017321 (cit. on p. 26).
[134] S. Matsuda et al., “Novel corner rounding process for shallow trench isolation utilizingmsts (micro-structure transformation of silicon),” in International Electron Devices
[135] T. Sato, N. Aoki, I. Mizushima, and Y. Tsunashima, “A new substrate engineering forthe formation of empty space in silicon (ess) induced by silicon surface migration,” inInternational Electron Devices Meeting 1999. Technical Digest (Cat. No.99CH36318),1999, pp. 517–520. DOI: 10.1109/IEDM.1999.824206 (cit. on pp. 27, 28).
[136] T. Sato and I. Mizushima, Semiconductor device including mosfet and isolation regionfor isolating the mosfet, US Patent 7,372,086, May 2008 (cit. on p. 27).
[137] S.-W. Ryu et al., “Overcoming the reliability limitation in the ultimately scaled dramusing silicon migration technique by hydrogen annealing,” in 2017 IEEE InternationalElectron Devices Meeting (IEDM), 2017, pp. 21.6.1–21.6.4. DOI: 10.1109/IEDM.2017.8268437 (cit. on p. 27).
[138] F. Zeng and M. Wong, “A self-scanned active-matrix tactile sensor realized usingsilicon-migration technology,” Journal of Microelectromechanical Systems, vol. 24,no. 3, pp. 677–684, 2015. DOI: 10.1109/JMEMS.2014.2344025 (cit. on p. 27).
[139] Y. Hu, F. Wang, and M. Wong, “An absolute capacitive pressure sensor based on asimit-fabricated vacuum cavity,” in 2021 21st International Conference on Solid-StateSensors, Actuators and Microsystems (Transducers), 2021, pp. 1170–1173. DOI: 10.1109/Transducers50396.2021.9495734 (cit. on p. 27).
[140] J. Xu, Z. Liu, J. Zheng, F. Qian, M. Wong, and Y. Yang, “Sealed-cavity bulk acousticresonator for subsequent fabrication and higher order mode,” Journal of Microelec-tromechanical Systems, pp. 1–3, 2023. DOI: 10.1109/JMEMS.2023.3338250(cit. on p. 27).
[141] Z. Liu, Y. Hu, G. E. Carranza, F. Wang, and M. Wong, “An intelligent gas analysissystem consisting of sensors and a neural network implemented using thin-film transis-tors,” in 2023 IEEE 36th International Conference on Micro Electro Mechanical Systems(MEMS), 2023, pp. 259–262. DOI: 10.1109/MEMS49605.2023.10052572(cit. on p. 27).
[142] F. Zeng and M. Wong, “A technology for monolithic mems-cmos integration andits application to the realization of an active-matrix tactile sensor,” in 2014 IEEE27th International Conference on Micro Electro Mechanical Systems (MEMS), 2014,pp. 445–448. DOI: 10.1109/MEMSYS.2014.6765672 (cit. on p. 27).108
[143] F. Zeng and M. Wong, “Silicon-migration technology for mems-cmos monolithicintegration,” in 2014 12th IEEE International Conference on Solid-State and IntegratedCircuit Technology (ICSICT), Oct. 2014, pp. 1–4. DOI: 10.1109/ICSICT.2014.7021216 (cit. on p. 28).
[144] W. W. Mullins, “Theory of thermal grooving,” Journal of Applied Physics, vol. 28, no. 3,pp. 333–339, 1957 (cit. on p. 28).
[145] F. Zeng and M. Wong, “A self-scanned active-matrix tactile sensor realized usingsilicon-migration technology,” Journal of Microelectromechanical Systems, vol. 24,no. 3, pp. 677–684, 2014 (cit. on p. 28).
[146] E. Kim et al., “Pattern recognition for selective odor detection with gas sensor arrays,”Sensors, vol. 12, no. 12, pp. 16 262–16 273, 2012 (cit. on p. 39).
[147] M. E. Castagna et al., “A high stability and uniformity w micro hot plate,” Sensors andActuators A: Physical, vol. 279, pp. 617–623, 2018. DOI: https://doi.org/10.1016/j.sna.2018.06.046 (cit. on p. 39).
[148] B. Behera and S. Chandra, “An innovative gas sensor incorporating zno￿￿uo nanoflakesin planar mems technology,” Sensors and Actuators B: Chemical, vol. 229, pp. 414–424,2016. DOI: https://doi.org/10.1016/j.snb.2016.01.079 (cit. onp. 39).
[149] B. Behera and S. Chandra, “A mems based acetone sensor incorporating zno nanowiressynthesized by wet oxidation of zn film,” Journal of Micromechanics and Microengi-neering, vol. 25, no. 1, p. 015 007, 2014 (cit. on p. 39).
[150] W.-J. Hwang, K.-S. Shin, J.-H. Roh, D.-S. Lee, and S.-H. Choa, “Development of micro-heaters with optimized temperature compensation design for gas sensors,” Sensors,vol. 11, no. 3, pp. 2580–2591, 2011 (cit. on p. 39).
[151] S. Roy, C. Sarkar, and P. Bhattacharyya, “A highly sensitive methane sensor withnickel alloy microheater on micromachined si substrate,” Solid-State Electronics, vol. 76,pp. 84–90, 2012 (cit. on p. 39).
[152] H. Pandya, S. Chandra, and A. Vyas, “Integration of zno nanostructures with mems forethanol sensor,” Sensors and Actuators B: Chemical, vol. 161, no. 1, pp. 923–928, 2012(cit. on p. 39).109
[153] B. Guo, A. Bermak, P. C. Chan, and G.-Z. Yan, “An integrated surface micromachinedconvex microhotplate structure for tin oxide gas sensor array,” IEEE Sensors Journal,vol. 7, no. 12, pp. 1720–1726, 2007 (cit. on p. 39).
[154] Y. Chen, M. Li, W. Yan, X. Zhuang, K. W. Ng, and X. Cheng, “Sensitive and low-powermetal oxide gas sensors with a low-cost microelectromechanical heater,” ACS omega,vol. 6, no. 2, pp. 1216–1222, 2021 (cit. on p. 39).
[155] H. Gao, H. Jia, B. Bierer, J. Wöllenstein, Y. Lu, and S. Palzer, “Scalable gas sensorsfabrication to integrate metal oxide nanoparticles with well-defined shape and size,”Sensors and Actuators B: Chemical, vol. 249, pp. 639–646, 2017 (cit. on p. 39).
[156] U. Frey, M. Graf, S. Taschini, K.-U. Kirstein, and A. Hierlemann, “A digital cmosarchitecture for a micro-hotplate array,” IEEE Journal of Solid-State Circuits, vol. 42,no. 2, pp. 441–450, 2007. DOI: 10.1109/JSSC.2006.889367 (cit. on p. 41).
[157] B. Guo, A. Bermak, P. C. Chan, and G.-Z. Yan, “A monolithic integrated 4×4 tin oxidegas sensor array with on-chip multiplexing and differential readout circuits,” Solid-StateElectronics, vol. 51, no. 1, pp. 69–76, 2007. DOI: https://doi.org/10.1016/j.sse.2006.10.015 (cit. on p. 41).
[158] A. Wieder and F. Neppl, “Cmos technology trends and economics,” IEEE Micro, vol. 12,no. 4, pp. 10–19, 1992. DOI: 10.1109/40.149732 (cit. on p. 41).
[159] K. Kandpal, A. Singh, and A. Srivastava, “Voltage-programmed pixel circuit designfor amoled displays,” in Contemporary Trends in Semiconductor Devices: Theory,Experiment and Applications, Springer, 2022, pp. 249–264 (cit. on p. 42).
[160] R. Triggs. “Display technology explained: A-si, ltps, amorphous igzo, and beyond.” Pub-lished on July 2, 2014. (2014), [Online]. Available: https://www.androidauthority.com/display-tech-explained-388248/ (visited on 01/07/2022) (cit. onp. 42).
[161] R. Pavelko et al., “Comparative study of nanocrystalline sno2 materials for gas sensorapplication: Thermal stability and catalytic activity,” Sensors and Actuators B: Chemi-cal, vol. 137, no. 2, pp. 637–643, 2009. DOI: https://doi.org/10.1016/j.snb.2008.12.025 (cit. on p. 52).
[162] M. J. Madou and S. R. Morrison, Chemical sensing with solid state devices. Elsevier,2012 (cit. on p. 52).110
[163] J. Watson, “The tin oxide gas sensor and its applications,” Sensors and Actuators,vol. 5, no. 1, pp. 29–42, 1984. DOI: https://doi.org/10.1016/0250-6874(84)87004-3 (cit. on p. 52).
[164] N. Yamazoe and K. Shimanoe, “1 - fundamentals of semiconductor gas sensors,” inSemiconductor Gas Sensors, ser. Woodhead Publishing Series in Electronic and OpticalMaterials, R. Jaaniso and O. K. Tan, Eds., Woodhead Publishing, 2013, pp. 3–34. DOI:https://doi.org/10.1533/9780857098665.1.3 (cit. on p. 52).
[165] Y. Masuda, “Recent advances in sno2 nanostructure based gas sensors,” Sensors andActuators B: Chemical, vol. 364, p. 131 876, 2022. DOI: https://doi.org/10.1016/j.snb.2022.131876 (cit. on p. 52).
[166] X. Liu et al., “Nanoparticle cluster gas sensor: Pt activated sno 2 nanoparticles for nh 3detection with ultrahigh sensitivity,” Nanoscale, vol. 7, no. 36, pp. 14 872–14 880, 2015(cit. on p. 53).
[167] B. Wang, L. Zhu, Y. Yang, N. Xu, and G. Yang, “Fabrication of a sno2 nanowire gassensor and sensor performance for hydrogen,” The Journal of Physical Chemistry C,vol. 112, no. 17, pp. 6643–6647, 2008 (cit. on p. 53).
[168] P. Stefanov, G. Atanasova, E. Manolov, Z. Raicheva, and V. Lazarova, “Preparationand characterization of sno2 films for sensing applications,” in Journal of Physics:Conference Series, IOP Publishing, vol. 100, 2008, p. 082 046 (cit. on p. 53).
[169] Y. Wang, X. Wu, Y. Li, and Z. Zhou, “Mesostructured sno2 as sensing material for gassensors,” Solid-State Electronics, vol. 48, no. 5, pp. 627–632, 2004 (cit. on p. 53).
[170] H. Xu, J. Li, P. Li, J. Shi, and X. Gao, “Effect of rare earth doping on electronic and gas-sensing properties of sno2 nanostructures,” Journal of Alloys and Compounds, vol. 909,p. 164 687, 2022 (cit. on p. 53).
[171] X. Kou et al., “High-performance acetone gas sensor based on ru-doped sno2 nanofibers,”Sensors and Actuators B: Chemical, vol. 320, p. 128 292, 2020 (cit. on p. 53).
[172] A. I. Khudiar and A. M. Oufi, “Influence of the aluminium doping on the physical andgas sensing properties of sno2 for h2 gas detection,” Sensors and Actuators B: Chemical,vol. 340, p. 129 633, 2021 (cit. on p. 53).
[173] Z. Lin, N. Li, Z. Chen, and P. Fu, “The effect of ni doping concentration on the gassensing properties of ni doped sno2,” Sensors and Actuators B: Chemical, vol. 239,pp. 501–510, 2017 (cit. on p. 53).111
[174] A. P. Lee and B. J. Reedy, “Temperature modulation in semiconductor gas sensing,”Sensors and Actuators B: Chemical, vol. 60, no. 1, pp. 35–42, 1999. DOI: https ://doi.org/10.1016/S0925-4005(99)00241-5 (cit. on pp. 53, 54).
[175] J. Mizsei, “How can sensitive and selective semiconductor gas sensors be made?”Sensors and Actuators B: Chemical, vol. 23, no. 2-3, pp. 173–176, 1995 (cit. on p. 53).
[176] X. Yin, L. Zhang, F. Tian, and D. Zhang, “Temperature modulated gas sensing e-nosesystem for low-cost and fast detection,” IEEE Sensors Journal, vol. 16, no. 2, pp. 464–474, 2016. DOI: 10.1109/JSEN.2015.2483901 (cit. on p. 53).
[177] J. Radhakrishnan, M. Kumara, and Geetika, “Effect of temperature modulation, on thegas sensing characteristics of zno nanostructures, for gases o2, co and co2,” SensorsInternational, vol. 2, p. 100 059, 2021. DOI: https://doi.org/10.1016/j.sintl.2020.100059 (cit. on p. 53).
[178] H. Ji, C. Mi, Z. Yuan, Y. Liu, H. Zhu, and F. Meng, “Multicomponent gas detectionmethod via dynamic temperature modulation measurements based on semiconductorgas sensor,” IEEE Transactions on Industrial Electronics, vol. 70, no. 6, pp. 6395–6404,2023. DOI: 10.1109/TIE.2022.3194629 (cit. on p. 53).
[179] F. Hossein-Babaei and A. Amini, “A breakthrough in gas diagnosis with a temperature-modulated generic metal oxide gas sensor,” Sensors and Actuators B: Chemical, vol. 166-167, pp. 419–425, 2012. DOI: https://doi.org/10.1016/j.snb.2012.02.082 (cit. on p. 53).
[180] G. Niu, C. Zhao, H. Gong, Z. Yang, X. Leng, and F. Wang, “Nio nanoparticle-decoratedsno2 nanosheets for ethanol sensing with enhanced moisture resistance,” Microsystems& Nanoengineering, vol. 5, no. 1, p. 21, 2019 (cit. on p. 54).
[181] N.-H. Kim, S.-J. Choi, D.-J. Yang, J. Bae, J. Park, and I.-D. Kim, “Highly sensitive andselective hydrogen sulfide and toluene sensors using pd functionalized wo3 nanofibersfor potential diagnosis of halitosis and lung cancer,” Sensors and Actuators B: Chemical,vol. 193, pp. 574–581, 2014. DOI: https://doi.org/10.1016/j.snb.2013.12.011 (cit. on p. 57).
[182] A. C. Society, “Cancer facts & figures,” American Cancer Society, 2016 (cit. on p. 57).
[183] G. Bersuker, M. Mason, and K. L. Jones, “Neuromorphic computing: The potential forhigh-performance processing in space,” Game Changer, pp. 1–12, 2018 (cit. on p. 65).112
[184] D. Ivanov, A. Chezhegov, M. Kiselev, A. Grunin, and D. Larionov, “Neuromorphicartificial intelligence systems,” Frontiers in Neuroscience, vol. 16, p. 1513, 2022 (cit. onp. 65).
[185] N. K. Upadhyay, H. Jiang, Z. Wang, S. Asapu, Q. Xia, and J. Joshua Yang, “Emergingmemory devices for neuromorphic computing,” Advanced Materials Technologies,vol. 4, no. 4, p. 1 800 589, 2019 (cit. on p. 65).
[186] X. Yan, J. H. Qian, V. K. Sangwan, and M. C. Hersam, “Progress and challenges formemtransistors in neuromorphic circuits and systems,” Advanced Materials, vol. 34,no. 48, p. 2 108 025, 2022 (cit. on p. 65).
[187] S. Gupta, P. Kumar, T. Paul, A. van Schaik, A. Ghosh, and C. S. Thakur, “Lowpower, cmos-mos2 memtransistor based neuromorphic hybrid architecture for wake-upsystems,” Scientific reports, vol. 9, no. 1, p. 15 604, 2019 (cit. on p. 65).
[188] A. Wali and S. Das, “Two-dimensional memtransistors for non-von neumann computing:Progress and challenges,” Advanced Functional Materials, p. 2 308 129, 2023 (cit. onp. 65).
[189] S. Majumdar, “Back-end cmos compatible and flexible ferroelectric memories forneuromorphic computing and adaptive sensing,” Advanced Intelligent Systems, vol. 4,no. 4, p. 2 100 175, 2022 (cit. on p. 65).
[190] M. Lederer et al., “Ferroelectric field effect transistors as a synapse for neuromorphicapplication,” IEEE Transactions on Electron Devices, vol. 68, no. 5, pp. 2295–2300,2021. DOI: 10.1109/TED.2021.3068716 (cit. on p. 65).
[191] Y. Sun, N. He, Y. Wang, Q. Yuan, and D. Wen, “Multilevel memory and artificialsynaptic plasticity in p (vdf-trfe)-based ferroelectric field effect transistors,” NanoEnergy, vol. 98, p. 107 252, 2022 (cit. on p. 65).
[192] H. Ling, D. A. Koutsouras, S. Kazemzadeh, Y. Van De Burgt, F. Yan, and P. Gkoupi-denis, “Electrolyte-gated transistors for synaptic electronics, neuromorphic computing,and adaptable biointerfacing,” Applied Physics Reviews, vol. 7, no. 1, 2020 (cit. on p. 65).
[193] Y. Li et al., “One transistor one electrolyte-gated transistor based spiking neural networkfor power-efficient neuromorphic computing system,” Advanced Functional Materials,vol. 31, no. 26, p. 2 100 042, 2021 (cit. on p. 65).113
[194] B.-W. Yao et al., “Non-volatile electrolyte-gated transistors based on graphdiyne/mos2with robust stability for low-power neuromorphic computing and logic-in-memory,”Advanced Functional Materials, vol. 31, no. 25, p. 2 100 069, 2021 (cit. on p. 65).
[195] S. Wang, D. W. Zhang, and P. Zhou, “Two-dimensional materials for synaptic electronicsand neuromorphic systems,” Science Bulletin, vol. 64, no. 15, pp. 1056–1066, 2019 (cit.on p. 65).
[196] C. Liu et al., “Two-dimensional materials for next-generation computing technologies,”Nature Nanotechnology, vol. 15, no. 7, pp. 545–557, 2020 (cit. on p. 65).
[197] V. K. Sangwan and M. C. Hersam, “Neuromorphic nanoelectronic materials,” Naturenanotechnology, vol. 15, no. 7, pp. 517–528, 2020 (cit. on p. 65).
[198] Y. Hu, Y. Wang, T. Lei, F. Wang, and M. Wong, “Neuromorphic implementation oflogic functions based on parallel dual-gate thin-film transistors,” IEEE Electron DeviceLetters, vol. 43, no. 5, pp. 741–744, 2022. DOI: 10.1109/LED.2022.3164684(cit. on p. 65).
[199] Y. Hu, T. Lei, Y. Wang, F. Wang, and M. Wong, “An artificial neural networkimplemented using parallel dual-gate thin-film transistors,” IEEE Transactions onElectron Devices, vol. 69, no. 10, pp. 5574–5579, 2022. DOI: 10.1109/TED.2022.3201836 (cit. on p. 65).
[200] Y. Hu, T. Lei, and M. Wong, “Parallel dual-gate thin-film transistors for sensing andneuromorphic computing,” in 2022 IEEE 16th International Conference on Solid-State and Integrated Circuit Technology (ICSICT), 2022, pp. 1–4. DOI: 10 . 1109 /ICSICT55466.2022.9963333 (cit. on p. 65).
[201] Y. Hu, T. Lei, Y. Wang, F. Wang, and M. Wong, “An artificial neural networkimplemented using parallel dual-gate thin-film transistors,” IEEE Transactions onElectron Devices, vol. 69, no. 10, pp. 5574–5579, 2022 (cit. on p. 70).
[202] A. Alabdulatif and N. N. Thilakarathne, “Bio-inspired internet of things: Current status,benefits, challenges, and future directions,” Biomimetics, vol. 8, no. 4, 2023. DOI: 10.3390/biomimetics8040373 (cit. on p. 80).
[203] C. Kim et al., “Artificial olfactory sensor technology that mimics the olfactory mecha-nism: A comprehensive review,” Biomaterials Research, vol. 26, no. 1, pp. 1–13, 2022(cit. on p. 80).114
[204] A. Sharma, R. Kumar, I. Aier, R. Semwal, P. Tyagi, and P. Varadwaj, “Sense of smell:Structural, functional, mechanistic advancements and challenges in human olfactoryresearch,” Current neuropharmacology, vol. 17, no. 9, pp. 891–911, 2019 (cit. on p. 80).
[205] E. Block, V. S. Batista, H. Matsunami, H. Zhuang, and L. Ahmed, “The role of metalsin mammalian olfaction of low molecular weight organosulfur compounds,” Naturalproduct reports, vol. 34, no. 5, pp. 529–557, 2017 (cit. on p. 80).
[206] D. Maßberg and H. Hatt, “Human olfactory receptors: Novel cellular functions outsideof the nose,” Physiological reviews, 2018 (cit. on p. 80).
[207] J. P. McGann, “Poor human olfaction is a 19th-century myth,” Science, vol. 356,no. 6338, eaam7263, 2017 (cit. on p. 80).
[208] J.-K. Han et al., “Artificial olfactory neuron for an in-sensor neuromorphic nose,”Advanced Science, vol. 9, no. 18, p. 2 106 017, 2022 (cit. on p. 80).
[209] S.-W. Lee, M. Kang, J.-K. Han, S.-Y. Yun, I. Park, and Y.-K. Choi, “An artificialolfactory sensory neuron for selective gas detection with in-sensor computing,” Device,vol. 1, no. 3, 2023 (cit. on p. 80).
[210] L. Liu, Y. Zhang, and Y. Yan, “Four levels of in-sensor computing in bionic olfaction:From discrete components to multi-modal integrations,” Nanoscale Horizons, vol. 8,no. 10, pp. 1301–1312, 2023 (cit. on p. 80).
[211] L. B. Buck, “Information coding in the vertebrate olfactory system,” Annual review ofneuroscience, vol. 19, no. 1, pp. 517–544, 1996 (cit. on pp. 82, 83).
[212] D. A. Storace and L. B. Cohen, “Measuring the olfactory bulb input-output transforma-tion reveals a contribution to the perception of odorant concentration invariance,” Naturecommunications, vol. 8, no. 1, p. 81, 2017 (cit. on pp. 83, 86).
[213] J. Chen et al., “Ultra-low-power smart electronic nose system based on three-dimensionaltin oxide nanotube arrays,” ACS nano, vol. 12, no. 6, pp. 6079–6088, 2018 (cit. on p. 90).
[214] Z. Song et al., “Wireless self-powered high-performance integrated nanostructured-gas-sensor network for future smart homes,” ACS nano, vol. 15, no. 4, pp. 7659–7667, 2021(cit. on p. 90).
[215] Z. Song et al., “Temperature-modulated selective detection of part-per-trillion no2 usingplatinum nanocluster sensitized 3d metal oxide nanotube arrays,” Small, vol. 18, no. 40,p. 2 203 212, 2022 (cit. on p. 90).115
[216] C. Wang et al., “Biomimetic olfactory chips based on large-scale monolithically inte-grated nanotube sensor arrays,” Nature Electronics, pp. 1–11, 2024 (cit. on p. 91).