Touch Detection Through Autocatalytic Transmission of Mechano-Chemical Signals

forthcoming

Life would be unthinkable without a sense of touch, for which we rely on densely distributed (mechano)sensors as part of our sensorimotor system, allowing us to grab objects and manipulate tools. From early on in life, reflexive movements (i.e., baby grasp reflex) ensure tight integration of sensing, signal processing, and movement. Such high-density local integration poses a fundamental challenge for robotics, as robotic sensing remains limited and expensive. Advancements in tactile sensing technologies based on new chemistry will be key enablers for future robots, particularly based on soft materials that are at the helm of a materials revolution for medical and general purpose robotics. With TactoChem, I will develop an artificial reflex arc for soft materials based on chemical mechanosensors that initiate chemical signaling cascades for movement. Chemical mechanosensors, similar to biological ones, are inherently nanoscale, scalable, and integrate with a material´s chemistry. Yet current mechanochemical tools are not designed for repeated production of strong signals and eliciting motion. Moreover, diffusive signaling is slow. TactoChem will establish new mechanophores – molecules that respond to mechanical force – and use autocatalysis to amplify their signal. To enable selective, even parallel signaling, and rapid movements of soft materials, we will leverage autocatalytic reactions locally delivered through networks of channels (synthetic vasculature). The resulting chemical analog of basic movement reflexes, akin to the knee-jerk or to baby grasp reflexes, will provide a first integrated chemical system for touch-based movement control. Mastering a sense of touch by chemical means will enable the design of novel robotic components made from soft materials without the need for electronic circuits and external power. As such, it has the power to fundamentally change how we think and design materials and robots.