An approach combining additive manufacturing and dielectrophoresis for 3D-structured flexible lead-free piezoelectric composites for electromechanical energy conversion

Additive manufacturing technology has promoted the development of piezoelectric devices, from the one-step moulding of micro-miniature devices to large-scale devices. In this study, we demonstrate a new approach relating to high-performance BaTiO3–polydimethylsiloxane (PDMS) composites for electromechanical energy conversion based on scalable 3D printing combined with dielectrophoresis, with judicious design via aligning the piezoelectric ceramic particles in the polymer matrix to enhance the piezoelectric generation performance. The obtained 3D-printed dielectrophoretically aligned BaTiO3–PDMS composite (15 vol%) exhibits an open-circuit output voltage and short-circuit current of
up to 80 V and 25 mA, respectively, with a maximum instantaneous power density of 242 mW cm 2, which is 9 times higher than that of a randomly dispersed nanoparticle 3D-printed composite. The work provides a novel strategy for the facile manufacturing of high-performance piezo-electronic composites and has great potential for applications related to wearable or implantable self-powered electronics.