An Edible Bistable Tilt Sensor Enabling Autonomous Operation of a Partially Eatable Rolling Robot

Edible electronics and robotics are emerging areas intimately bridging food science and engineering to deliver technology using food-derived materials. Edible devices offer unprecedented opportunities thanks to features such as bioresorbability, nutritional value, associated taste, minimal toxicity, and sustainability. However, several challenges need to be addressed to bring edible devices closer to reality. Although prototypal edible sensors are available, rotation sensors—an essential component for orientation perception—are still missing. Integrating sensors, actuators, and structural components into an edible system also remains a challenge due to the lack of processes and standardization. Here the first edible tilt sensor is presented. Starting from a commercial nonedible bistable tilt sensor, each material is replaced with edible equivalents using simple and straightforward fabrication approaches. Its functionality is validated in the first implementation of an autonomous and partly edible rolling robot, which has a nutritional value of 807.5 kcal and integrates gelatin actuators, an array of tilt sensors, and an edible wheeled frame. The robot works in closed loop, perceiving its orientation and input for actuation from the sensors. These findings may pave the way to novel edible technologies, from drug delivery for wild animals to health applications.