Dual-modal piezotronic transistor for highly sensitive vertical force sensing and lateral strain sensing

Nat Commun. 2023 Oct 9;14(1):6315. doi: 10.1038/s41467-023-41983-3.

Abstract

Mechanical sensors are mainly divided into two types (vertical force sensing and lateral strain sensing). Up to now, one sensor with two working modes is still a challenge. Here, we demonstrate a structural design concept combing a piezoelectric nano/microwire with a flexible polymer with protrusions that enables a dual-modal piezotronic transistor (DPT) with two working modes for highly sensitive vertical force sensing and lateral strain sensing. For vertical force sensing, DPT exhibits a force sensitivity up to 221.5 N-1 and a minimum identifiable force down to 21 mN, corresponding to a pressure sensitivity of 1.759 eV/MPa. For lateral strain sensing, DPT can respond to a large compression strain (~5.8%) with an on/off ratio up to 386.57 and a gauge factor up to 8988.6. It is a universal design that can integrate vertical force sensing and lateral strain sensing into only one nanodevice, providing a feasible strategy for multimodal devices.