Taxel-Addressable Matrix of Vertical-Nanowire Piezotronic Transistors for Active and Adaptive Tactile Imaging

Abstract

Designing, fabricating, and integrating arrays of nanodevices into a functional system are the key to transferring nanoscale science into applicable nanotechnology. We report large-array three-dimensional (3D) circuitry integration of piezotronic transistors based on vertical zinc oxide nanowires as an active taxel-addressable pressure/force sensor matrix for tactile imaging. Using the piezoelectric polarization charges created at a metal-semiconductor interface under strain to gate/modulate the transport process of local charge carriers, we designed independently addressable two-terminal transistor arrays, which convert mechanical stimuli applied to the devices into local electronic controlling signals. The device matrix can achieve shape-adaptive high-resolution tactile imaging and self-powered, multidimensional active sensing. The 3D piezotronic transistor array may have applications in human-electronics interfacing, smart skin, and micro- and nanoelectromechanical systems.

Piezotronic Effect in Solution-Grown p-Type ZnO Nanowires and Films

“…4,7,8,11,12 Here we demonstrate the first p-type ZnO NWs based piezotronic transistors, which extends the concept of piezotronics and its potential applications in the fields of flexible electronics and optoelectronics. As-prepared Sb-doped ZnO NWs were sonicated in ethanol and transferred onto PET substrates.…”

“…6 A wide variety of novel applications based on the piezotronic effect have been demonstrated including strain sensors, 7 logic units, 8 memory cells, 9 electrochemical devices, 10 and tactile imaging arrays. 11 However, the aforementioned piezotronic devices were all fabricated using intrinsically n-type ZnO and few studies of piezotronics based on p-type materials, especially p-type ZnO, have been done. In order to develop a full understanding of the theory of piezotronics and enable novel applications in electronics, optoelectronics, smart MEMS/ NEMS, and human-machine interfacing, 4,11−14 it is essential to investigate the feasibility of p-type piezoelectric semiconductors for piezotronic applications.…”

High-sensitivity accelerometer composed of ultra-long vertically aligned barium titanate nanowire arrays

“…Furthermore, the sensitivity of BaTiO 3 NW sensor (B50 mV g À 1 ) is demonstrated to be higher than the sensitivity of the ZnO NW sensor (B2.5 mV g À 1 ) when direct comparison was performed under the same testing conditions. However, semiconducting ZnO NWs exhibit other useful functionalities such as the piezotronic and piezo-phototronic effects that utilize strain-induced piezopotential as the gate voltage to tune carrier generation, transport and separation across interface/junction, which is of immense interest in nano-electronic and optoelectronic devices 36,37 .…”

Human Skin Based Triboelectric Nanogenerators for Harvesting Biomechanical Energy and as Self-Powered Active Tactile Sensor System

“…17À19 Moreover, the piezotronic effect has been used to fabricate a twoterminal transistor array matrix for detecting strain distribution with a density of 8464 devices per 1 cm square. 20 An external power source is required to drive these tactile sensors. Self-powered nanotechnology utilizes energy harvesters instead of external power sources or conventional batteries to drive the sensors.…”