Periodic Reporting for period 3 - GEL-SYS (Smart HydroGEL SYStems – From Bioinspired Design to Soft Electronics and Machines) Reporting period: 2021-01-01 to 2022-06-30 Summary of the context and overall objectives of the project Hydrogels evolved as versatile building blocks of life – we all are in essence gel-embodied soft machines. Drawing inspiration from the diversity found in living creatures, GEL-SYS develops a set of concepts, materials approaches and design rules for wide ranging classes of soft, hydrogel-based electronic, ionic and photonic devices focusing on – (1) tough interfaces, (2) gel electronics and (3) soft robotics. With this, GEL-SYS will create a technology blurring the lines between our physical world and the digital sphere.Our project enables a high level of complexity in soft, yet tough biomimetic devices and machines by introducing nature-inspired instant strong bonds between hydrogels and antagonistic materials – from soft and elastic to hard and brittle. Building on these newly developed interfaces, GEL-SYS will pursue biocompatible hydrogel electronics with iontronic transducers and large area multimodal sensor arrays for a new class of medical tools and health monitors. We will foster the current soft revolution of robotics and electronics with new, bioderived and biodegradable yet resilient materials that minimize the ecological footprint of our societies technological advance. Autonomous operation will be a central question in soft systems, tackled with tough stretchable batteries and energy harvesting from mechanical motion on small and large scales with soft membranes. GEL-SYS will use our experience on soft, “imperceptible” electronics and devices. By fusing this technology platform with tough hydrogels - nature’s most pluripotent ingredient of soft machines - we aim to create the next generation of bionic systems. The envisioned hybrids promise new discoveries in the nonlinear mechanical responses of soft systems, and will allow exploiting triggered elastic instabilities for unconventional locomotion. Sustainable materials and concepts such as energy harvesting from renewable sources will allow us to advance technology with imminent impact on our society but without adverse effects on our ecosystem. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far When looking at the animate world around us, and in particular at the “building blocks” that we are made of, we will find that nature has developed intricate ways to unite a wide range of antagonistic materials into highly sophisticated “hybrid soft robots”. From hard and resilient as bones teeth, elastic and tough as muscles and tendons all the way to soft and squishy as the brain – seamless interfaces between soft and hard are found everywhere in and around us. At the beginning of GEL-SYS, we took this intricacy as inspiration for our quest to develop the soft electronic and robotic systems of the future. We developed a method for instant tough bonding of hydrogels to a wide variety of materials spanning hard and brittle to soft and stretchable in a frugal and effective way using dispersions of quickly reacting synthetic glues. This enabled us to employ tough and stretchy hydrogels to create a variety of soft systems, from electronic sensor skins interfacing with human skin to tunebale soft lenses inspired by the human eye all the way to stretchable batteries as effective power supply of wearable electronics. While pursuing the goal of GEL-SYS of developing technologies that ever more intimately and seamlessly integrate in our daily lives, we inevitably arrived at a key question: Can we develop advanced technologies in a sustainable way? Facing ever-growing amounts of e-waste – 50 million tons of it in 2019 alone – sustainability must become a driving principle of research. New trends, from bio-inspired robotics to personalized healthcare and monitoring, create undreamt-of possibilities for a worthwhile future. Here, innovation that is sustainable is innovation that lasts. Within GEL-SYS, we recently contributed to this overarching goal by developing a new class of resilient yet bioderived and biodegradable hydrogels that closes the gap between sustainability and performance. Based on the biopolymer gelatin, this biogel is highly durable with outstanding elastic characteristics, yet degrades fully when disposed. It self-adheres, is rapidly healable and derived entirely from natural and food-safe constituents. By merging all the favourable attributes in one material that is easy to reproduce and scalable at low production costs under ambient conditions, the developments within GEL-SYS are a step towards durable, life-like soft robotic and electronic systems that are sustainable and closely mimic their natural antetypes. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) Within GEL-SYS, we envision a close collaboration between the technologies of the future and us humans. Safe and intimate contact between man and machine requires rethinking of established concepts, turning “hard” into “soft”. Within GEL-SYS, we recently developed new forms of soft electromagnetic actuators that have the principle of an electric motor at their core, but make use of soft materials exclusively to build fast, controllable and save soft machines that find applications from grippers and soft actuators to eventually micron scaled machines that can navigate within the human body, guided noninvasively by Magnetic Resonance Imaging systems. We support these innovations by new concepts for high-performance soft and stretchable batteries for autonomous wearable electronics as imperceptible user interfaces or in mobile healthcare monitoring. Together with new fundamental insights into how to build ultra-fast but inherently safe soft actuators from sustainable materials such as natural rubber, GEL-SYS will continue to stretch the boundaries of soft and hybrid materials, triggering the evolution of soft systems and guiding them into a sustainable future. The vision of GEL-SYS: A technology blurring the lines between the biological and digital spheres Self-adherent tough yet biodegradable electronic multimodal sensor skin Elefant inspired soft robotic actuator from resilient biogel with textile exoskeleton
