High performance piezocomposites for flexible device application†
Flexible piezocomposites have emerged as promising materials for highly durable wearable devices. Here, we propose a new design strategy, namely particle alignment engineering, to develop high performance flexible piezocomposites by dielectrophoresis (DEP). An ultrahigh piezoelectric voltage coefficient (g33) of 600 × 10−3 V m N−1 is achieved by a composite of (Ba0.85Ca0.15)(Ti0.90Zr0.10)O3 (BCZT) particles aligned in a polydimethylsiloxane (PDMS) matrix. To the best of our knowledge, this g33 value is by far the highest ever achieved in piezocomposites. The significantly improved poling electric voltage applied to the BCZT particles and hugely enhanced stress-transfer capability of the aligned composite synergistically contribute to the record-high piezoelectric response in flexible piezocomposites. The fabricated flexible piezoelectric touch sensor and wearable keyboard possess an excellent sensitivity and cycling stability, which demonstrate a promising strategy for exploring high performance piezocomposites for flexible device application.