High‐Performance Pressure Sensors Based on Shaped Gel Droplet Arrays

Abstract

Polymer gel‐based pressure sensors offer numerous advantages over traditional sensing technologies, including excellent conformability and integration into wearable devices. However, challenges persist in terms of their performance and manufacturing technology. In this study, a method for fabricating gel pressure sensors using a hydrophobic/hydrophilic patterned surface is introduced. By shaping and fine‐tuning the droplets of the polymer gel prepolymerization solution on the patterned surface, remarkable sensitivity improvements compared to unshaped hydrogels have been achieved. This also showcased the potential for tailoring gel pressure sensors to different applications. By optimizing the configuration of the sensor array, an uneven conductive gel array is fabricated, which exhibited a high sensitivity of 0.29 kPa−1 in the pressure range of 0–30 kPa, while maintaining a sensitivity of 0.13 kPa−1 from 30 kPa up to 100 kPa. Furthermore, the feasibility of using these sensors for human motion monitoring is explored and a conductive gel array for 2D force detection is successfully developed. This efficient and scalable fabrication method holds promise for advancing pressure sensor technology and offers exciting prospects for various industries and research fields.

Review of Droplet Printing Technologies for Flexible Electronic Devices: Materials, Control, and Applications

“…Especially in the field of micro flexible electronic advices [ 18 ], droplet printing technology has unique advantages in preparing micro-level structures [ 80 ], making it suitable for fields such as optoelectronic displays [ 81 ] and micro/nano system integration. The microsystem compatibility of this technology makes it an ideal choice for manufacturing various microdevices such as microsensors, microreactors, and flexible sensors [ 21 , 39 ].…”

“…Li [ 90 ] deposited ZnO thin films using an electrospray method and produced an alcohol gas sensor, exhibiting good repeatability and response stability in the target gas. Wang [ 21 ] introduced a method for preparing gel pressure sensors using hydrophobic/hydrophilic patterned surface. Through optimization of the array configuration of the sensor, an uneven conductive gel array was fabricated.…”

“…Researchers are not only exploring efficient and controllable methods for droplet generation, but are also focusing on optimizing the performance of droplet arrays in practical applications. For instance, in the field of biosensing [ 21 , 22 ], optimization of the preparation process for droplet arrays can enhance the binding efficiency of droplets with biomolecules, thereby achieving sensitive and rapid detection. In materials science, droplet arrays can be utilized to fabricate ordered structures of inorganic materials [ 23 , 24 ] or organic optoelectronic materials [ 25 , 26 , 27 , 28 ] that can subsequently be used to investigate the relationship between their macroscopic properties and microscopic structures.…”

Hydrophilic/ Omniphobic droplet arrays for high-throughput and quantitative enzymology

“…The open format of these arrays facilitates easy reagent addition or sampling by 'stamping' slides vertically together 41,42 . Demonstrating their utility and flexibility, superhydrophobic/superhydrophilic droplet arrays have already been used for a variety of high-throughput screening applications, including synthesizing chemicals, screening cells and drugs, and designing materials [43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59] . To date, however, such wettability-patterned droplet arrays have not been used for in vitro enzyme expression and downstream characterization of the expressed enzymes.…”