Flexible Pseudocapacitive Iontronic Tactile Sensor Based on Microsphere‐Decorated Electrode and Microporous Polymer Electrolyte for Ultrasensitive Pressure Detection

Abstract

Wearable sensor as the initial terminal is in great requirement for people pursuing healthy life. High‐performance tactile sensors are the guarantee of accurate pressure information acquisition. Herein, a flexible iontronic tactile sensor is developed by utilizing a highly conductive poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) thin film decorated with polymethyl methacrylate microspheres as pseudocapacitive electrode and a porous polyurethane foam composited with Na+/Cl− ion‐enriched polyvinyl alcohol gel as polymer electrolyte through a facile method of solution‐casting followed by freeze‐drying. By taking advantages of both high pseudocapacitance and rationally designed microstructures, the developed tactile sensor shows an ultrahigh sensitivity (≈162.90 kPa−1), a broad detection range (≈160 kPa), a low detection limit (≈30 Pa), a fast response time (≈25 ms), and excellent repeatability and durability. Thanks to the ultrahigh sensitivity, the sensor is capable of detecting subtle pressures caused by dynamic micromotions such as touching a sandpaper surface, dropping water droplets, and adding water into a beaker. Application of a smart glove mounted with such sensor unit and array for a fast and accurate Braille recognition is also demonstrated. The proposed facile and efficient strategy of fabricating flexible ultrasensitive tactile sensors will be favorable to various wearable subtle pressure sensing applications.

Wide-Range Linear Iontronic Pressure Sensor with Two-Scale Random Microstructured Film for Underwater Detection

“…In order to further verify the linearity optimization effect of TRM, the capacitance−pressure response curves of electrolyte membranes with monolayer graphene electrode and different structures are shown in Figure 3f. The relative capacitance change curve of devices with only second-scale microstructures is similar to the results of other works using sandpaper-grafted microstructures, 32,38,39 and its linear range is not as good as that of our flexible iontronic sensor using TRM film (R 2 = 0.994). The response curve of the sensor is estimated by least square fitting.…”

An Ultrahighly Pressure Sensitive Electronic Fish Skin for Underwater Wave Sensing

“…The Ti 3 C 2 T x was prepared by etching the Al layers in the MAX phase (Ti 3 AlC 2 ) and simultaneously removing them through sonication. 25 It is worth noting that the MXene nanosheets possess distinct hierarchical structure, and their diluted dispersoid solution shows a Tyndall effect (Figure S2a,b). Moreover, multiple uniform nanopores are clearly displayed on the entire basal surface of HGO, which was synthesized by etching the carbon atoms of graphene oxide (GO) with H 2 O 2 (Figure S3).…”

“…The pseudocapacitive iontronic sensing originated from reversible faradic redox reactions has displayed the highest interfacial capacitance and capacitive sensitivity among all pressure devices, , as well as exhibited ultrahigh signal-to-noise ratio performance to suppress the influence of parasitic capacitance, which holds much potential in next generation pressure sensors . The intensity of the reaction involved in pseudocapacitance depends on the active materials of the electrode.…”

Recent advances in flexible and soft gel-based pressure sensors

“…Ionogels are composed of a 3D network crosslinked by the polymer matrix containing an ionic liquid (IL) and are ideal candidate materials for alternative hydrogels. Ionogels not only possess high ionic conductivity, strong mechanical property and good thermal, chemical and electrochemical stability, but also have a unique anti-drying property (i.e., no crystallization and volatilization at low and high temperatures) [53][54][55][56] . Compared to hydrogels, ionogels show excellent performance in dry environments, even under vacuum conditions.…”