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-TeO2 triangular microwires was governed by a [110] axis. The α-TeO2 microwires belong to the tetragonal structure with a space group of P41212. 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-TeO2–PDMS composite film, the shear forces were formed on the microwires׳ surface along with the [110] and/or [1¯1¯0] poling axis. As a result of the antisymmetric element of e14 and −e25 in the α-TeO2 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-TeO2 will not be canceled out even if the microwires׳ 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-TeO2 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.