Skin-inspired electronics:emerging semiconductor devices and systems

Current electronics are driven by advanced microfabrication for fast and efficient information processing.In spite of high performance,these wafer-based devices are rigid,non-degradable,and unable to autonomous repair.Skin-inspired electronics have emerged as a new class of devices and systems for next-generation flexible and wearable electronics.The technology gains inspiration from the structures,properties,and sensing mechanisms of the skin,which may find a broad range of applications in cutting-edge fields such as healthcare monitoring,human-machine interface,and soft robotics/prostheses.Practical demands have fueled the development of electronic materials with skin-like properties in terms of stretchability,self-healing capability,and biodegradability.These materials provide the basis for functional sensors with innovative and biomimetic designs.Further system-level integrations and optimizations enable new forms of electronics for real-world applications.This review summarizes recent advancements in this active area and speculates on future directions.

Carbon flowers as electrocatalysts for the reduction of oxygen to hydrogen peroxide

Small-scale and decentralized production of H_(2)O_(2)via electrochemical reduction of oxygen is of great benefit,especially for sanitization,air and water purification,as well as for a variety of chemical processes.The development of low-cost and highperformance catalysts for this reaction remains a key challenge.Carbon-based materials have drawn substantial research efforts in recent years due to their advantageous properties,such as high chemical stability and high tunability in active sites and morphology.Deeper understanding of structure–activity relationships can guide the design of improved catalysts.We hypothesize that mass transport to active sites is of great importance,and herein we use carbon materials with unique flower-like superstructures to achieve high activity and selectivity for O2 reduction to H_(2)O_(2).The abundance of nitrogen active sites controlled by pyrolysis temperature resulted in high catalytic activity and selectivity for oxygen reduction reaction(ORR).The flower superstructure showed higher performance than the spherical nanoparticles due to greater accessibility to the active sites.Chemical activation improves the catalysts’performances further,driving the production of H_(2)O_(2)to a record-setting rate of 816 mmol·gcat^(−1)·h^(−1)using a bulk electrolysis setup.This work demonstrates the development of a highly active catalyst for the sustainable production of H_(2)O_(2)through rational design and synthetic control.The understanding from this work provides further insight into the design of future carbon-based electrocatalysts.

High-performance oxygen reduction and evolution carbon catalysis： From mechanistic studies to device integration

The development of high-performance and low-cost oxygen reduction and evolution catalysts that can be easily integrated into existing devices is crucial for the wide deployment of energy storage systems that utilize O2-H2O chemistries, such as regenerative fuel cells and metal-air batteries. Herein, we report an NHB-activated N-doped hierarchical carbon （NHC） catalyst synthesized via a scalable route, and demonstrate its device integration. The NHC catalyst exhibited good performance for both the oxygen reduction reaction （ORR） and the oxygen evolution reaction （OER）, as demonstrated by means of electrochemical studies and evaluation when integrated into the oxygen electrode of a regenerative fuel cell. The activities observed for both the ORR and the OER were comparable to those achieved by state-of-the-art Pt and Ir catalysts in alkaline environments. We have further identified the critical role of carbon defects as active sites for electrochemical activity through density functional theory calculations and high-resolution TEM visualization. This work highlights the potential of NHC to replace commercial precious metals in regenerative fuel cells and possibly metal-air batteries for cost-effective storage of intermittent renewable energy.

Skin-Inspired Electronics Enabled by Supramolecular Polymeric Materials

Next-generation electronics that intimately interact with the human body would play crucial roles in future health monitors and early disease diagnosis.Skin-inspired electronics have been rapidly growing in the past decade to emulate the remarkable sensory and responsive nature of the human skin tissue.

UV-laser-machined stretchable multi-modal sensor network for soft robot interaction

Soft robotic hands can facilitate human-robot interaction by allowing robots to grasp a wide range of objects safely and gently.However,their performance has been hampered by a lack of suitable sensing systems.We present a flexible and stretchable multimodal sensor network integrated with a soft robotic hand.The design of wired sensors on a flexible metalized film was embodied through a manufacturing approach that uses both UV laser metal ablation and plastic cutting simultaneously to create sensor electrode and stretchable conductive wires in a Kirigami pattern into a single network.We evaluated the interconnects and sensors by measuring an impedance change to each external stimulus and showed that are not substantially affected by stretching the network.With the sensor sheet wrapped around a soft robotic gripper,we demonstrated several interaction scenarios,including a warm burrito for food handling,and a warm baby doll for medical applications.

Using Periodic Dynamic Polymers to Form Supramolecular Nanostructures

CONSPECTUS:Many emerging applications including wearable electronics and e-skins,soft robotics and actuators,and biomaterials require material platforms with precisely controlled mechanical,electrical,thermal,and optical properties.The practical realization of devices for these applications is often restricted not by the lack of novel designs but rather by the sparsity of materials with the required properties.Dynamic polymers,which employ both covalent and noncovalent linkages,offer a promising platform for the design of new materials because of their highly tunable chemical structures.