Self-healing actuatable electroluminescent fibres.

Alternating-current electroluminescent fibres are promising candidates as light sources for smart textiles and soft machines. However, physical damage from daily use causes device deterioration or failure, making self-healable electroluminescent fibres attractive. In addition, soft robots could benefit from light-emitting combined with magnetically actuated functions.

Frictionless multiphasic interface for near-ideal aero-elastic pressure sensing.

Conventional pressure sensors rely on solid sensing elements. Instead, inspired by the air entrapment phenomenon on the surfaces of submerged lotus leaves, we designed a pressure sensor that uses the solid-liquid-liquid-gas multiphasic interfaces and the trapped elastic air layer to modulate capacitance changes with pressure at the interfaces. By creating an ultraslippery interface and structuring the electrodes at the nanoscale and microscale, we achieve near-friction-free contact line motion and thus near-ideal pressure-sensing performance.

Implant-to-implant wireless networking with metamaterial textiles.

Implanted bioelectronic devices can form distributed networks capable of sensing health conditions and delivering therapy throughout the body. Current clinically-used approaches for wireless communication, however, do not support direct networking between implants because of signal losses from absorption and reflection by the body. As a result, existing examples of such networks rely on an external relay device that needs to be periodically recharged and constitutes a single point of failure.

Size-dependent bending of a rectangular polymer film.

Inhomogeneous swelling of polymer films in liquid environments may find applications in soft actuators and sensors. Among them, fluoroelastomer based films bend up spontaneously once they are placed on an acetone-soaked filter paper. The stretchability and dielectric properties of a fluoroelastomer is attractive in the fields of soft actuators and sensors, making in-depth studies on and understanding of fluoroelastomer bending behaviors important.

Technology Roadmap for Flexible Sensors.

Humans rely increasingly on sensors to address grand challenges and to improve quality of life in the era of digitalization and big data. For ubiquitous sensing, flexible sensors are developed to overcome the limitations of conventional rigid counterparts. Despite rapid advancement in bench-side research over the last decade, the market adoption of flexible sensors remains limited.

Dynamic Modeling of Intrinsic Self-Healing Polymers Using Deep Learning.

The properties of self-healing polymers are traditionally identified through destructive testing. This means that the mechanics are explored in hindsight with either theoretical derivations and/or simulations. Here, a self-healing property evolution using energy functional dynamical (SPEED) model is proposed to predict and understand the mechanics of self-healing of polymers using images of cuts dynamically healing over time.

Macromolecule conformational shaping for extreme mechanical programming of polymorphic hydrogel fibers.

Mechanical properties of hydrogels are crucial to emerging devices and machines for wearables, robotics and energy harvesters. Various polymer network architectures and interactions have been explored for achieving specific mechanical characteristics, however, extreme mechanical property tuning of single-composition hydrogel material and deployment in integrated devices remain challenging. Here, we introduce a macromolecule conformational shaping strategy that enables mechanical programming of polymorphic hydrogel fiber based devices.

A wireless and battery-free wound infection sensor based on DNA hydrogel.

The confluence of wireless technology and biosensors offers the possibility to detect and manage medical conditions outside of clinical settings. Wound infections represent a major clinical challenge in which timely detection is critical for effective interventions, but this is currently hindered by the lack of a monitoring technology that can interface with wounds, detect pathogenic bacteria, and wirelessly transmit data. Here, we report a flexible, wireless, and battery-free sensor that provides smartphone-based detection of wound infection using a bacteria-responsive DNA hydrogel.

Wirelessly operated bioelectronic sutures for the monitoring of deep surgical wounds.

Monitoring surgical wounds post-operatively is necessary to prevent infection, dehiscence and other complications. However, the monitoring of deep surgical sites is typically limited to indirect observations or to costly radiological investigations that often fail to detect complications before they become severe. Bioelectronic sensors could provide accurate and continuous monitoring from within the body, but the form factors of existing devices are not amenable to integration with sensitive wound tissues and to wireless data transmission.

Scaling Metal-Elastomer Composites toward Stretchable Multi-Helical Conductive Paths for Robust Responsive Wearable Health Devices.

Stretchable electronics have advanced rapidly and many applications require high repeatability and robustness under various mechanical deformations. It has been described here that how a highly stretchable and reliable conductor composite made from helical copper wires and a soft elastomer, named eHelix, can provide mechanically robust and strain-insensitive electronic conductivity for wearable devices. The reversibility of the mechanical behavior of the metal-elastomer system has been studied using finite element modeling methods.

Progress and Roadmap for Intelligent Self-Healing Materials in Autonomous Robotics.

Robots are increasingly assisting humans in performing various tasks. Like special agents with elite skills, they can venture to distant locations and adverse environments, such as the deep sea and outer space. Micro/nanobots can also act as intrabody agents for healthcare applications.

Near-hysteresis-free soft tactile electronic skins for wearables and reliable machine learning.

Electronic skins are essential for real-time health monitoring and tactile perception in robots. Although the use of soft elastomers and microstructures have improved the sensitivity and pressure-sensing range of tactile sensors, the intrinsic viscoelasticity of soft polymeric materials remains a long-standing challenge resulting in cyclic hysteresis. This causes sensor data variations between contact events that negatively impact the accuracy and reliability.

Super Tough and Self-Healable Poly(dimethylsiloxane) Elastomer via Hydrogen Bonding Association and Its Applications as Triboelectric Nanogenerators.

Poly(dimethylsiloxane) (PDMS) as one of the electron-drawing materials has been widely used in triboelectric nanogenerators (TENG), which is expected to generate electron through friction and required to endure dynamic loads. However, the nature of the siloxane bond and the low interchain interaction between the methyl side groups result in low fracture energy in PDMS elastomers. Here, a strategy that combined the advantages of the dynamic of hierarchical hydrogen bonding and phase-separation-like structure was adopted to improve the toughness of PDMS elastomers.

Osmosis-Powered Hydrogel Microneedles for Microliters of Skin Interstitial Fluid Extraction within Minutes.

Hydrogel microneedle patch enables the extraction of skin interstitial fluid (ISF) through in situ swelling in a minimally invasive manner without assistance of mechano-chemical peripherals. However, existing hydrogel microneedles require tens of minutes with multistep process to collect sufficient volume (1 mL) for effective analysis. This study introduces an osmolyte-powered hydrogel microneedle patch that can extract ISF three times faster than the existing platforms and provide in situ analysis of extracted biomarkers.

Wireless battery-free body sensor networks using near-field-enabled clothing.

Networks of sensors placed on the skin can provide continuous measurement of human physiological signals for applications in clinical diagnostics, athletics and human-machine interfaces. Wireless and battery-free sensors are particularly desirable for reliable long-term monitoring, but current approaches for achieving this mode of operation rely on near-field technologies that require close proximity (at most a few centimetres) between each sensor and a wireless readout device. Here, we report near-field-enabled clothing capable of establishing wireless power and data connectivity between multiple distant points around the body to create a network of battery-free sensors interconnected by proximity to functional textile patterns.

A transparent, self-healing and high-κ dielectric for low-field-emission stretchable optoelectronics.

Stretchable optoelectronic materials are essential for applications in wearable electronics, human-machine interfaces and soft robots. However, intrinsically stretchable optoelectronic devices such as light-emitting capacitors usually require high driving alternating voltages and excitation frequencies to achieve sufficient luminance in ambient lighting conditions. Here, we present a healable, low-field illuminating optoelectronic stretchable (HELIOS) device by introducing a transparent, high permittivity polymeric dielectric material.

Design and applications of stretchable and self-healable conductors for soft electronics.

Soft and conformable electronics are emerging rapidly and is envisioned as the future of next-generation electronic devices where devices can be readily deployed in various environments, such as on-body, on-skin or as a biomedical implant. Modern day electronics require electrical conductors as the fundamental building block for stretchable electronic devices and systems. In this review, we will study the various strategies and methods of designing and fabricating materials which are conductive, stretchable and self-healable, and explore relevant applications such as flexible and stretchable sensors, electrodes and energy harvesters.

A neuro-inspired artificial peripheral nervous system for scalable electronic skins.

The human sense of touch is essential for dexterous tool usage, spatial awareness, and social communication. Equipping intelligent human-like androids and prosthetics with electronic skins-a large array of sensors spatially distributed and capable of rapid somatosensory perception-will enable them to work collaboratively and naturally with humans to manipulate objects in unstructured living environments. Previously reported tactile-sensitive electronic skins largely transmit the tactile information from sensors serially, resulting in readout latency bottlenecks and complex wiring as the number of sensors increases.

Soft Electronically Functional Polymeric Composite Materials for a Flexible and Stretchable Digital Future.

Flexible/stretchable electronic devices and systems are attracting great attention because they can have important applications in many areas, such as artificial intelligent (AI) robotics, brain-machine interfaces, medical devices, structural and environmental monitoring, and healthcare. In addition to the electronic performance, the electronic devices and systems should be mechanically flexible or even stretchable. Traditional electronic materials including metals and semiconductors usually have poor mechanical flexibility and very limited elasticity.

Self-Healing Electronic Materials for a Smart and Sustainable Future.

The survivability of living organisms relies critically on their ability to self-heal from damage in unpredictable situations and environmental variability. Such abilities are most important in external facing organs such as the mammalian skin. However, the properties of bulk elemental materials are typically unable to perform self-repair.

Advancing the frontiers of silk fibroin protein-based materials for futuristic electronics and clinical wound-healing (Invited review).

The present review will introduce the basic concepts of silk-based electronics/optoelectronics including the latest technological advances on the use of silk fibroin in combination with other functional components, with an emphasis on improving the performance of next-generation silk-based materials. It also highlights the patterning of silk fibroin to produce micro/nano-scale features, as well as the functionalization of silk fibroin to impart antimicrobial (i.e.