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,

Conventional refrigeration relies on hazardous agents, contributing to global warming. Soft, cheap, biodegradable solid-state elastocaloric cooling based on natural rubber offers an environmental friendly alternative. However, no such practical cooler has been developed, as conventional soft elastocaloric designs are not fast enough to ensure adiabaticity.In this work, we combine snap-through instability with strain-induced crystallization and achieve a sub-100 ms quasi-adiabatic cycling which is 30 times faster than previous design.Negligible heat exchange in expansion/contraction stages combined with the latent heat of phase transitions result in a giant elastocaloric crystallization effect. The rubber-based all-soft heat pump enables a specific cooling power of 20.9 W/g, a heat-flux of 256 mW/cm 2 , a coefficient of performance of 4.7 and a single-stage temperature span between hot and cold reservoirs of 7.9 K (full adiabatic temperature change of rubber membrane exceeding 23 K).The pump permits a compact all-soft voltage-actuated setup, opening up the opportunity of a viable plug-in-ready cooling device.