Highly sensitive active-powering pressure sensor enabled by integration of double-rough surface hydrogel and flexible batteries

Abstract

A conductive, elastic, and biocompatible hybrid network hydrogel was prepared by cross-linking of locust bean gum, polyvinyl alcohol, and carbon nanotubes, yielding a rough top surface and smooth bottom surface. The merging of the two pieces of hydrogel flat face to flat face forms a highly elastic hydrogel with double-rough surfaces. A piezoresistive sensor assembled with the double-rough surface hydrogel sandwiched between two carbon cloth electrodes exhibits a high sensitivity (20.5 kPa-1, 0-1kPa), a broad detection range (0.1–100 kPa) and a reliable response for 1000 cycles. The rough contact area between the hydrogels and the carbon cloth is found critical in achieving ultra-high sensitivities in the low-pressure range. Moreover, further monolithic integration of the sensor with a flexible solid-state zinc ion battery ensures the self-powering of the sensor for various human motions detection applications.

Self-Healing Flexible Pressure Sensor for Human Motion Detection Based on Silver-Nanoparticle-Modified Polyimide Membranes

“…Figure and Table S1 show the sensing performance comparison between the fabricated flexible pressure sensor and other high-performance piezoresistive sensors reported in the literature. ,,,− It is found that most pressure sensors cannot achieve high sensitivity and wide linear range simultaneously through material selection and structural design, exhibiting a trade-off between these two properties. In this work, the PI@Ag sensors possess both high sensitivity (197 kPa –1 ) in a medium-pressure region (10–20 kPa) as well as relatively high sensitivity (13.73 kPa –1 and 47.6 kPa –1 ) in the low- (100 Pa–10 kPa) and high-pressure regions (20–50 kPa).…”

Anti‐Freezing Wearable Tactile Sensors Prepared by Laser Processing of Crumpled Xanthan Gum‐Based Hydrogels

“…c) Sensitivity and detection range of our sensor with DR‐5 W hydrogels in comparison with other reported sensors based on hydrogels. [ 18,20,30–34 ] d) The changes in relative current of the sensor fabricated with DR‐5 W hydrogels pressed by different amounts of rice grain. The inset shows optical image of a rice grain during testing.…”

“…The sensitivity and detection range of the proposed sensor were also compared with other sensors based on hydrogels. [18,20,[30][31][32][33][34] As illustrated in Figure 3c, the sensor obtained with DR-5 W hydrogels showed superior performance. Therefore, the sensor with DR-5 W hydrogels was selected for subsequent experiments.…”

“…We also compared the response time, detection limit, and durability of our sensor and those of the previous hydrogel sensors (Table S1, Supporting Information). [18,20,[30][31][32][33][34] Our sensor has no outstanding advantage in terms of response time, detection limit, and durability. Further studies are needed to improve the response time, detection limit, and durability of our sensor.…”

“…The presence of multiple reactive sites in natural biopolymer also allows modification and functionalization through various strategies. [16] Several studies have so far fabricated piezoresistive materials based on natural biopolymer-based hydrogels, such as silk fibroin-based, [17] locust bean gum (LBG)-based, [18] cellulosicbased, [19] and chitosan-based. [20] These sensors based on natural biopolymer-based hydrogels exhibited high sensitivities in a low detection range coupled with excellent flexibility.…”