Electronic devices have advanced from their heavy, bulky origins to become smart, mobile appliances. Nevertheless, they remain rigid, which precludes their intimate integration into everyday life. Flexible, textile and stretchable electronics are emerging research areas and may yield mainstream technologies. Rollable and unbreakable backplanes with amorphous silicon field-effect transistors on steel substrates only 3 μm thick have been demonstrated. On polymer substrates, bending radii of 0.1 mm have been achieved in flexible electronic devices. Concurrently, the need for compliant electronics that can not only be flexed but also conform to three-dimensional shapes has emerged. Approaches include the transfer of ultrathin polyimide layers encapsulating silicon CMOS circuits onto pre-stretched elastomers, the use of conductive elastomers integrated with organic field-effect transistors (OFETs) on polyimide islands, and fabrication of OFETs and gold interconnects on elastic substrates to realize pressure, temperature and optical sensors. Here we present a platform that makes electronics both virtually unbreakable and imperceptible. Fabricated directly on ultrathin (1 μm) polymer foils, our electronic circuits are light (3 g m(-2)) and ultraflexible and conform to their ambient, dynamic environment. Organic transistors with an ultra-dense oxide gate dielectric a few nanometres thick formed at room temperature enable sophisticated large-area electronic foils with unprecedented mechanical and environmental stability: they withstand repeated bending to radii of 5 μm and less, can be crumpled like paper, accommodate stretching up to 230% on prestrained elastomers, and can be operated at high temperatures and in aqueous environments. Because manufacturing costs of organic electronics are potentially low, imperceptible electronic foils may be as common in the future as plastic wrap is today. Applications include matrix-addressed tactile sensor foils for health care and monitoring, thin-film heaters, temperature and infrared sensors, displays, and organic solar cells.

Photovoltaic technology requires light-absorbing materials that are highly efficient, lightweight, low cost and stable during operation. Organolead halide perovskites constitute a highly promising class of materials, but suffer limited stability under ambient conditions without heavy and costly encapsulation. Here, we report ultrathin (3 μm), highly flexible perovskite solar cells with stabilized 12% efficiency and a power-per-weight as high as 23 W g(-1). To facilitate air-stable operation, we introduce a chromium oxide-chromium interlayer that effectively protects the metal top contacts from reactions with the perovskite. The use of a transparent polymer electrode treated with dimethylsulphoxide as the bottom layer allows the deposition-from solution at low temperature-of pinhole-free perovskite films at high yield on arbitrary substrates, including thin plastic foils. These ultra-lightweight solar cells are successfully used to power aviation models. Potential future applications include unmanned aerial vehicles-from airplanes to quadcopters and weather balloons-for environmental and industrial monitoring, rescue and emergency response, and tactical security applications.

A strategy for bonding water-rich hydrogels to diverse materials for electronic skins, energy storage, and soft optics is reported.

Biodegradable and biocompatible elastic materials for soft robotics, tissue engineering or stretchable electronics with good mechanical properties, tunability, modifiability, or healing properties drive technological advance, yet they are not durable under ambient conditions nor combine all attributes in a single platform. We have developed a versatile gelatin-based biogel, which is highly resilient with outstanding elastic characteristics yet degrades fully when disposed. It self-adheres, is rapidly healable and derived entirely from natural and food-safe constituents. We merge for the first time all favorable attributes in one material that is easy to reproduce, scalable and low-cost in production under ambient conditions. This biogel is a step towards durable, lifelike soft robotic and electronic systems that are sustainable and closely mimic their natural antetypes. Main: In 2025, an estimated 6 million tons of garbage will be generated per day 1 , with tech disposables being a rapidly growing contributor. End-of-lifetime appliances contain valuable materials that are laborious in recovery or toxic substances that are readily released into nature through landfilling or improper treatment 2. Biodegradable 3-6 and transient systems 7 are promising routes towards closing the loop on waste generation and create new opportunities for secure systems, but often at the cost of compromises in performance. Complex biological systems bridge this gap. They unite seemingly antagonistic properties-tough yet adaptive, durable and self-healing yet degradable-allowing them to perform a myriad of intricate tasks. Embodiments of technologies that intimately interface with humans naturally benefit from mimicking such soft, functional forms. A range of biomimetic systems 8 including soft machines 9 and electronic skins 10 achieve a high level of functionality by introducing self-healing 11,12 , intrinsic stretchability 13 , or the insightful merging of soft-to-hard materials 14. Waste flow issues and in vivo applications that avoid multiple surgeries are tackled with inextensible devices in the form of edible 3,15 and transient electronics 7,16. However, introducing stretchability to degradable devices remains challenging. Recent approaches focusing on stretchable biodegradable sensors 5 require expensive materials and are still wired to bulky measurement systems hindering implementation as wearable devices. Challenges here stem from the diverse material requirements,

The emergence of smart electronics, human friendly robotics and supplemented or virtual reality demands electronic skins with both tactile and touchless perceptions for the manipulation of real and virtual objects. Here, we realize bifunctional electronic skins equipped with a compliant magnetic microelectromechanical system able to transduce both tactile—via mechanical pressure—and touchless—via magnetic fields—stimulations simultaneously. The magnetic microelectromechanical system separates electric signals from tactile and touchless interactions into two different regions, allowing the electronic skins to unambiguously distinguish the two modes in real time. Besides, its inherent magnetic specificity overcomes the interference from non-relevant objects and enables signal-programmable interactions. Ultimately, the magnetic microelectromechanical system enables complex interplay with physical objects enhanced with virtual content data in augmented reality, robotics, and medical applications.