Periodic Reporting for period 4 - GEL-SYS (Smart HydroGEL SYStems – From Bioinspired Design to Soft Electronics and Machines)
Periodo di rendicontazione: 2022-07-01 al 2023-06-30
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 created technology blurring the lines between our physical world and the digital sphere.
Our project enabled 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 pursued biocompatible hydrogel electronics with iontronic transducers and large area multimodal sensor arrays for a new class of medical tools and health monitors. We fostered 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 is a central question in soft systems, tackled herein with stretchable, biodegradable batteries and energy harvesting from mechanical motion on small and large scales with soft membranes. GEL-SYS leveraged 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 took major steps towards the next generation of bionic systems. Sustainable materials and concepts such as energy harvesting from renewable sources allowed us to advance technology with imminent impact on our society but without adverse effects on our ecosystem.
Our project enabled 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 pursued biocompatible hydrogel electronics with iontronic transducers and large area multimodal sensor arrays for a new class of medical tools and health monitors. We fostered 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 is a central question in soft systems, tackled herein with stretchable, biodegradable batteries and energy harvesting from mechanical motion on small and large scales with soft membranes. GEL-SYS leveraged 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 took major steps towards the next generation of bionic systems. Sustainable materials and concepts such as energy harvesting from renewable sources allowed us to advance technology with imminent impact on our society but without adverse effects on our ecosystem.
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 all the way to stretchable batteries as power supply. 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 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. What’s more, these gels can be readily 3D printed for dexterous soft grippers that are proprio-and exteroceptive. The team’s efforts culminated in the development of the first high-power stretchable and biodegradable batteries, an essential step towards autonomous and sustainable soft devices. Future robots will benefit from lightweight, efficient and fast “muscles” that are readily controllable. Polymer-based electrostatic actuators are promising here, within GEL-SYS we developed their first biodegradable embodiments that do not compromise in performance, but are compostable once no longer needed. By merging materials innovations with scalable, low cost fabrication methods, GEL-SYS is a step towards durable, life-like soft robotic and electronic systems that are sustainable and closely mimic their natural antetypes. The numerous achievements of the project have so far led to 30 peer reviewed journal publications and the foundation of a startup company. They were disseminated by the team at the major conferences in the field, as well as through wide press coverage in public media and outreach activities such as at the ARS Electronica media arts festival.
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 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. We took the next steps towards such soft machines by developing the fastest ever millimeter-scale soft robots that locomote with up to 72 bodylengths per second, that is in relation to their size faster than a cheetah or a sports car. GEL-SYS supports these innovations by new concepts for high-performance soft and stretchable batteries for autonomous wearable electronics. Following a different approach, where we tapped into the power of sunlight and ambient illumination, we developed wearable sensors that are able to continuously analyze biomarkers within sweat and inform on the wellbeing of a patient entirely without the need for batteries but energized by newly developed flexible, efficient and stable solar cells. 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 stretched the boundaries of soft and hybrid materials, triggering the evolution of soft systems and guiding them into a sustainable future. Unexpected at first, but potentially an important milestone in our struggle to combat climate change is our demonstration of efficient cooling engines that exploit the giant elastocaloric effect in elastomers and thus bear the potential to render conventional, ecologically harmful cooling gasses obsolete. Equally promising are our first steps towards establishing naturally grown fungal materials – mycelium skins – as alternative for fossil fuel-based polymers in the fabrication of electronic circuitry. These materials require minimal resources in their production and biodegrade in household compost at the end of their useful lifespan, thus contributing to the reduction of electronic waste.