Ultrahigh Sensitive Wearable Pressure Sensors Based on Reduced Graphene Oxide/Polypyrrole Foam for Sign Language Translation

Abstract

Pressure sensors have attracted worldwide attention due to their extensive application requirements in wearable devices, flexible touch display, soft robotics, and health monitoring. Although many pressure sensors have been developed, it still remains a grand challenge to achieve ultrahigh sensitivity with good stability in low‐pressure regions. Herein, the polypyrrole (PPy) is introduced to reduced graphene oxide foam (rGOF) via in situ solventless polymerization to manufacture rGO/PPyF, which significantly enhances the sensitivity and stability of the derived sensors. The as‐fabricated sensor demonstrates an ultrahigh sensitivity of 32.32 kPa−1 in the pressure region of 0–21 Pa, high resolution, and excellent cycling stability. Furthermore, the pressure sensor can transform different hand gestures to distinguishable electrical signals in sign language translation, which indicates that the pressure sensor has a bright application prospect in wearable devices and human–computer interaction.

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

“…Wearable and flexible pressure sensors could be attached to the clothing or the skin to monitor external pressure, motion signals, or physiological signals under continuous working conditions [1][2][3][4] . Therefore, wearable pressure sensors are important for muscle motion analysis, sign language translation, breath monitoring, flexible electronic skins, and speech recognition applications [5][6][7][8] . There are four types of wearable sensors with different sensing mechanisms: i) piezo capacitance 3,9 , ii) triboelectricity 5 , iii) piezoresistivity [10][11][12] , and iv) piezoelectricity 13 .…”

Intercalation Engineering of 2D Materials at Macroscale for Smart Human–Machine Interface and Double‐Layer to Faradaic Charge Storage for Ions Separation

“…Two sign languages “Hello” and “thank you” can be accurately distinguished and converted into electrical signals by using graphene foam/ppy‐based pressure sensors ( Figure a). [ 75 ] Additionally, graphene composite hydrogel shows the real‐time human motion activity using a strain sensor using a smartphone application (Figure 7b). [ 112 ] Harvesting of human energy can be feasible since the human body can provide thermal energy as a stable heat source.…”

Biologically Emulated Flexible Sensors With High Sensitivity and Low Hysteresis: Toward Electronic Skin to a Sense of Touch

“…[39] In addition to the aforementioned drawbacks, existing pressure sensors are cumbersome to manufacture and utilize expensive materials, which is a major limitation to their development. [11,40,41] The conventional microstructure processing methods include chemical deposition, inversion, and photolithography. Among the previous methods, the 3D printing mold in the inversion form is very popular among researchers, which possesses the advantages of simple manufacture and reliable repeatability.…”