Fully Elastic and Metal‐Free Tactile Sensors for Detecting both Normal and Tangential Forces Based on Triboelectric Nanogenerators

Abstract

A tactile sensor should be able to detect both normal and tangential forces, which is mandatory for simulating human hands, but this fundamental function has been overlooked by most of the previous studies. Here, based on a triboelectric nanogenerator (TENG) with single-electrode mode, the fully elastic and metal-free tactile sensor that can detect both normal and tangential forces is proposed. With tiny burr arrays on the contact interface to facilitate the elastic deformation, the detected normal pressure by the device can reach to 1.5 MPa with a sensitivity of about 51.43 kPa V −1 , and a large range of tangential forces can be detected ranging from 0.5 to 40 N with rough sensitivity of 0.83 N V −1 (0.5-3 N) and 2.50 N V −1 (3-40 N). Meanwhile, the applied tangential forces from different directions can also be clearly distinguished by the four-partitioned electrode structure. Moreover, a shield film is coated on the top surface of the device, which can screen the electrostatic interference and enhance the repeatability of the device. The demonstrated concept of this self-powered tactile sensor has excellent applicability for industrial robotics, human-machine interactions, artificial intelligence, etc.

Self‐Powered Tactile Sensor Array Systems Based on the Triboelectric Effect

“…On the contrary, the output voltage of the tactile sensor based on bidirectional unidirectional Ag NF electrodes remains unaltered, demonstrating a remarkable stretchability. In addition to the normal pressure detect, a tactile sensor based on single‐electrode mode which can detect both normal and tangential forces has been recently demonstrated . The tiny arrays of carbon black on the contact surface are prepared to facilitate the elastic deformation, which largely promotes the pressure detection range up to 1.5 MPa and sensitivity of 51.43 V kPa −1 .…”

“…A one‐stop self‐powered implantable triboelectric sensor which can provide continuous monitoring of multiple physiological and pathological signs are fabricated by Ma et al Reported by Guo et al, a self‐powered auditory sensor for an external hearing aid in intelligent robotic applications is fabricated . Additionally, a fully elastic and metal‐free tactile sensor based on TENG, which can detect both normal and tangential forces is proposed by Ren et al…”

Bioinspired Triboelectric Nanogenerators as Self‐Powered Electronic Skin for Robotic Tactile Sensing

“…[31] Recently, Pu et al presented an ultrastretchable and transparent TENG (stretchability of 1160% and transparency of 96.2% for visible light) e-skin sensor for tactile sensing. [33] Meanwhile, bioinspired design has been an attractive strategy for the enhancement of e-skin sensor measurement sensitivity. [33] Meanwhile, bioinspired design has been an attractive strategy for the enhancement of e-skin sensor measurement sensitivity.…”

“…[38] Boutry et al proposed an interlocking structure for the fabrication of capacitive e-skin sensors to distinguish the direction of applied pressure. [33] The cone-like PDMS microstructures on both the triboelectric layers are fabricated through the replication of the surface of the C. zebrine leaf, which demonstrates relatively uniform cone-like morphology, as shown in Figure 1b and inset. An alternative and efficient method to achieve bioinspired microstructures for sensitivity enhancement is to replicate the hierarchical structures of natural plants.…”

Human–Machine Interfacing Enabled by Triboelectric Nanogenerators and Tribotronics

“…Among the various approaches toward this goal of HMIs, the triboelectric nanogenerator (TENG) and tribotronics have emerged as promising alternatives in recent years. The TENG, based on the coupling of contact electrification and electrostatic induction, was invented by Wang and co‐workers .…”