High-performance Biopolymer Cryogels for Transient Sensing Ecology-drones 

Aerial robots can autonomously collect temporal and spatial high-resolution environmental data. This data can then be utilized to develop mathematical ecology models to understand the impact of climate change on our habitat. In case of the drone's malfunction the incorporated materials can threaten vulnerable environments. The recent introduction of transient robotics has enabled the development of biodegradable, environmental sensing drones capable of degrading in their environment. However, manufacturing methods for environmental sensing transient drones are rarely discussed. In this work, we highlight a manufacturing framework and material selection process featuring biopolymer-based, high-strength composite cryogels and printed carbon-based electronics for transient drones. We found that gelatin and cellulose based cryogels mechanically outperform other biopolymer composites while having a homogeneous micro-structure and high stiffness-to-weight ratio. The selected materials are used to manufacture a flying-wing air-frame, while the incorporated sensing skin is capable of measuring the elevons' deflection angles as well as ambient temperature. Our results demonstrate how gelatin-cellulose cryogels can be used to manufacture lightweight transient drones while printing carbon conductive electronics is a viable method for designing sustainable, integrated sensors. The proposed methods can be used to guide the development of lightweight and rapidly degrading robots, featuring eco-friendly sensing capabilities. Corresponding author(s) Email:     fabian.wiesemueller@empa.ch , mirko.kovac@empa.ch