Advances in Biodegradable Electronic Skin: Material Progress and Recent Applications in Sensing, Robotics, and Human–Machine Interfaces

Abstract

The signals generated by these stimuli are transferred to the central neural network and brain to provide an appropriate response. In addition, biological skin possesses unique characteristics, such as stretchability, self-healing ability, and mechanical toughness. [1][2][3] It also provides an effective barrier against ambient elements such as chemicals, gases, radiation, and external biological agents.Electronic skin (e-skin) is an artificial smart skin composed of various electronic sensors distributed on a single uniform surface or stacked on multiple surfaces. It mimics some of the biological skin senses and provides a promising sensing platform for key application areas such as wearable sensors, robotics, and prosthetics (Figure 1). [1,[4][5][6][7][8][9][10][11] However, serious concerns have arisen regarding the production of electronic waste (e-waste), the influence of e-skin on human health, the safety of wearable electronic devices, costs, and environmental limitations. These concerns have encouraged researchers to develop biocompatible, renewable, sustainable, and biodegradable flexible wearable detection devices and biosensing platforms. [12][13][14][15][16] Biological skin regularly regenerates the old superficial layer of the epidermis with new skin cells during the healing process. Inspired by this natural degradation cycle, artificial biodegradable skin-based electronics should be designed for programmable degradation, in contrast to conventional electronic materials. To achieve this goal, the development of biocompatible, environmentally friendly electronic systems that can be used for the fabrication of biodegradable and sustainable e-skins is important.Various low-cost, nontoxic, renewable, and natural substances and polymer-based materials that can be applied to the development of sustainable, biodegradable e-skins and alleviate the environmental and health risks of e-waste materials are available. [17][18][19][20][21][22] E-waste disrupts the biological activity of microbial enzymes and their metabolisms, which decreases the resistance and the diversity of soil-based microbial communities. [23] In addition, in the human body, the accumulation of metals and metalloids used in the fabrication of conventional electronics can cause a range of biophysical malfunctions and diseases, such as liver damage by Cu, behavioral disorders by Pb, and lung cancer and kidney damage by Cd. [24][25][26][27] The rapid growth of the electronics industry and proliferation of electronic materials and telecommunications technologies has led to the release of a massive amount of untreated electronic waste (e-waste) into the environment. Consequently, catastrophic environmental damage at the microbiome level and serious human health diseases threaten the natural fate of the planet. Currently, the demand for wearable electronics for applications in personalized medicine, electronic skins (e-skins), and health monitoring is substantial and growing. Therefore, "green" characteristics such as biodegradability, self-healin...

Surface Wrinkling for Flexible and Stretchable Sensors

“…to other sensor types that only operate based on a single external stimulus. [1,3] The capability of multiple stimuli detection endows multimodal sensors unique advantages in temperature and pressure sensing, texture recognition and material discrimination, and vibration distribution mapping compared to the other conventional sensors. Various types of multimodal sensors have been developed for the fabrication of high-performance sensors using surface wrinkled micro and nanostructures.…”

“…Owing to their unique physical characteristics, such as highperformance, stability, and durability, under strained conditions, stretchable and flexible sensors have received increased researchers' attention for developing the next generation of electronics. [1] In the future, flexible sensors are expected to play critical roles in boosting the reliability of skin-inspired electronics, from soft electronic skins (e-skins), [2][3][4][5] humanmachine interfaces (HMIs), [6,7] soft robotics, [8,9] and physiological monitoring. [10][11][12][13] Such biocompatible electronic platforms, Recent advances in nanolithography, miniaturization, and material science, along with developments in wearable electronics, are pushing the frontiers of sensor technology into the large-scale fabrication of highly sensitive, flexible, stretchable, and multimodal detection systems.…”

Applications of MXenes in human-like sensors and actuators

“…For example, poly(vinylidene fluoride-cohexafluoropropylene) (P(VDF-HFP)) serves as conducting gate electrodes in top-gated transistors [238]. Often, one can choose biodegradable polymers, plant-derived biomass [239], natural wax [240], silk fibroin [241,242], and chitosan [243] as supporting substrates for hosting device fabrication.…”

Zebra-inspired stretchable, biodegradable radiation modulator for all-day sustainable energy harvesters

“…Although the results accomplished technological advances in a diverse range of research realms, there has been little consideration for systems that are critically linked to the sustainability of ecosystems by alleviating the environmental and economic challenges arising from the notable increase in end-of-life electronic waste and disposal. In this context, management and reduction of wastes can be realized via bioresorbable elements whose degradable and nontoxic behaviors in biological environments have already been verified by various reports associated with implantable biomedical electronics (13)(14)(15)(16), wearable electronic systems (17,18), drug carriers (19,20), and tissue scaffolds (21,22). Because the chemical bonds and tunable nano/microstructures of polymers are known to absorb LWIR light and reflect the solar spectrum effectively (10), fibrous biodegradable polymer membranes may represent an attractive starting point.…”