Aerosol‐Jet Printed Fine‐Featured Triboelectric Sensors for Motion Sensing

Abstract

the relatively simple mechanism involved in converting mechanical energy into electrical signals, [15,16] wide material selection, [17,18] and light weight. [19] Triboelectric generators produce active electric output due to mechanical motion-driven contact electrification and charge induction. These generators can also be used as sensors, where the output signal can be monitored for sensing movement. [20][21][22][23][24] One particular type of triboelectric sensor designed for motion sensing, based on grated electrode structures on triboelectric surfaces, has been found to be potentially reliable, of high resolution, and direction sensitive with a wide selection of feasible materials. [25,26] Typically, these sensors comprise multiple alternating strips of two different triboelectric materials for contact electrification, and grated comb-like electrodes or interdigitated electrodes for charge induction. A commonly reported device structure involves a "mover" that slides over a "stator," with the contacting surface made up of triboelectric material strips, and the grated electrodes positioned on the backside of both the mover and the stator to form a sliding mode triboelectric sensor. [21] The relative sliding motion between the two different materials gives rise to a triboelectric charge that is picked up by the electrodes. If the electrodes are positioned only on the backside of the stator, then this structure gives rise to a freestanding mode triboelectric sensor (no electrical contact is needed from the mover). [27] To achieve high resolution, the metallic electrode gratings must be narrow (submillimeter), usually achieved via photolithography, [28] physical deposition, [26,29] or ion-etching [30] methods. These methods are not particularly cost effective and are generally inefficient for fast prototyping. At the same time, polymers that have good triboelectric properties are difficult to fabricate into the desired fine structures or finely patterned strips by the conventional lithography or physical deposition methods. This has led to the vast majority of the current grated-structure triboelectric sensors being built with metal strips as the active triboelectric material, [18,31] even though these are not particularly well-suited for triboelectric applications. Reports on all polymer-grated triboelectric sensors are thus tellingly rare, even though such devices could potentially offer better resolution and higher signal-to-noise ratios in motion sensing applications.Triboelectric motion sensors, based on the generation of a voltage across two dissimilar materials sliding across each other as a result of the triboelectric effect, have generated interest due to the relative simplicity of the typical grated device structures and materials required. However, these sensors are often limited by poor spatial and/or temporal resolution of motion due to limitations in achieving the required device feature sizes through conventional lithography or printing techniques. Furthermore, the reliance on metallic components t...

Fully Printed, Wireless, Stretchable Implantable Biosystem toward Batteryless, Real‐Time Monitoring of Cerebral Aneurysm Hemodynamics

“…[14,15] Widely used wireless interrogation for implantation primarily includes radiofrequency communication and inductive coupling. [18][19][20] One study developed a freestanding interconnect for use as a strain sensor and humidity sensor. [6,16] However, they still show limited readout distances, less than 3 cm in air, but wirelessly transmitted signals attuenate rapidly in tissue.…”

“…AJP, compared to conventional processes, allows for faster and reliable fabrication and scalable manufacturing via direct printing, digital designing, and optimized control. However, previous demonstrations of AJP‐based electronics have been limited to passive electrical components, development of transistors, and flexible substrates . One study developed a freestanding interconnect for use as a strain sensor and humidity sensor .…”

Self-Powered Sensors and Systems Based on Nanogenerators

“…Therefore, the mechanical motion sensors based on TENG are widely studied by researchers due to their simple and flexible structures, highly integrated level, and low costs [60]. They can monitor the motion parameters of moving objects and be applied to different research fields [61,62]. The triboelectric sensors for different forms of motion can be divided into three types-position sensors, speed sensors, and acceleration sensors.…”

A Review and Perspective for the Development of Triboelectric Nanogenerator (TENG)-Based Self-Powered Neuroprosthetics

“…It is noted that there are alternative ways to generate high-frequency current pulses without any switching mechanisms. One of the most conventional ways is by using the grating TENG working in sliding mode [ 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 ]. By using the proper design for the width and spacing of the grating electrode, high-frequency current pulses can be generated even with slow sliding.…”