A review of electronic skin: soft electronics and sensors for human health

Abstract

Electronic skin (e-skin) is able to monitor physiological signals, providing great potential in healthcare. This review briefly introduces the advanced information of e-skins for wearable sensors, such as their materials and integrate strategies.

MXene‐Based Conductive Organohydrogels with Long‐Term Environmental Stability and Multifunctionality

“…Bionic sensors based on conductive hydrogels that are able to transduce external stimuli (e.g., strain or pressure) into detectable electronic signals (e.g., resistance, voltage, current, or capacitance) have shown advanced applications in the fields of personal healthcare, motion detection, and artificial intelligence. [ 1–5 ] Generally, the water‐rich structure makes the hydrogel behave like a solid, while still enabling fast ion transportation like liquid. [ 6,7 ] However, conventional conductive hydrogels using pure water as dispersion medium are generally plagued by two problems: the freezing‐induced hardening issue at subzero temperatures, which significantly limits the operating temperature range of the hydrogel.…”

“…personal healthcare, motion detection, and artificial intelligence. [1][2][3][4][5] Generally, the water-rich structure makes the hydrogel behave like a solid, while still enabling fast ion transportation like liquid. [6,7] However, conventional conductive hydrogels using pure water as dispersion medium are generally plagued by two problems: the freezing-induced hardening issue at subzero temperatures, which significantly limits the operating temperature range of the hydrogel.…”

Transduction Mechanisms, Micro-Structuring Techniques, and Applications of Electronic Skin Pressure Sensors: A Review of Recent Advances

“…In 2020, a paper presented different pressure sensors (except triboelectric), some well-implemented micro-structuring techniques and resultant micro-structures [ 58 ]. Another paper reviewed materials for e-skin devices and different types of sensors (pressure, strain, temperature, and multifunctional), with a brief overview over self-powered units and array devices [ 59 ]. The group of Caofeng Pan explored piezoresistive pressure sensors, their key parameters, materials, and designs [ 60 ].…”

“…Overall, the majority of the published reviews cover not only pressure sensors but also other sensors and e-skin units, therefore, the description of pressure sensors is typically not very detailed [ 3 , 4 , 46 , 48 , 49 , 52 , 53 , 55 , 56 , 57 , 59 ]. Especially concerning the first reviews, triboelectric pressure sensors are not mentioned, possibly because their development is more recent, or the differences between the different types of pressure sensors are not clearly stated and explored [ 3 , 4 , 5 , 45 , 46 , 47 , 48 , 50 , 52 , 53 , 56 , 58 , 60 ].…”

“…Especially concerning the first reviews, triboelectric pressure sensors are not mentioned, possibly because their development is more recent, or the differences between the different types of pressure sensors are not clearly stated and explored [ 3 , 4 , 5 , 45 , 46 , 47 , 48 , 50 , 52 , 53 , 56 , 58 , 60 ]. Micro-structuring is a highly relevant topic in the field of e-skin pressure sensors, as it will be explored in the next sections, yet it is not emphasized in most works, or not broadly covered [ 3 , 4 , 5 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 56 , 57 , 58 , 59 , 60 , 61 ]. Some reviews are also not very extensive in the presentation of applications where the pressure sensors can be explored [ 3 , 4 , 5 , 46 , 51 , 53 , 54 , 55 , 56 , 58 , 59 , 60 , 61 ].…”