Abstract
We have demonstrated the practicality of an ultrasensitive wrist-wear pulse active sensor that was first made using tellurium dioxide triangular microwires. The unusual growth direction of the α-TeO 2 triangular microwires was governed by a [110] axis. The α-TeO 2 microwires belong to the tetragonal structure with a space group of P4 1 2 1 2. Due to the gravitational force effect, the triangular microwires were encapsulated by polydimethylsiloxane (PDMS) and underwent a natural gravity-driven settling process during the PDMS solidification process, leading to the triangular microwires being placed on the substrate with a randomly horizontal orientation. When a compressive stress was applied to the α-TeO 2 -PDMS composite film, the shear forces were formed on the microwires[U+05F3] surface along with the [110] and/or [1-1-0] poling axis. As a result of the antisymmetric element of e 14 and -e 25 in the α-TeO 2 structure, the triangular microwires have created an obviously piezoelectric potential (piezopotential) ~3.2V that was perpendicularly established along with the poling axis. On the basis of the unique triangular morphology and its physical properties, the piezopotential of the α-TeO 2 will not be canceled out even if the microwires[U+05F3] tips are pointed towards each other. Thus, the piezopotential can be accumulated across the top and bottom electrodes of the nanogenerator (active sensor). The α-TeO 2 triangular microwires can be acted upon as a useful active sensor for detecting the tiny physical motions, for instance, a pulse driven sensor, air pressure, and touchless control of smart devices.