Self-sensing cellulose structures with design-controlled stiffness

Robots are often used for sensing and sampling in natural environments. Within this area, soft robots have become increasingly popular for these tasks because their mechanical compliance makes them safer to interact with. Unfortunately, if these robots break while working in vulnerable environments, they create potentially hazardous waste. Consequently, the development of compliant, biodegradable structures for soft, eco-robots is a relevant research area that we explore here. Cellulose is one of the most abundant biodegradable materials on earth, but it is naturally very stiff, which makes it difficult to use in soft robots. Here, we look at both biologically and kirigami inspired structures that can be used to reduce the stiffness of cellulose based parts for soft robots up to a factor of 19 000. To demonstrate this, we build a compliant force and displacement sensing structure from microfibrillated cellulose. We also describe a novel manufacturing technique for these structures, provide mechanical models that allow designers to specify their stiffness, and conclude with a description of our structure's performance

Forest drones for environmental sensing and nature conservation

Protecting our nature and biodiversity is essential. For this purpose, remote sensing robotic platforms are increasingly explored to collect spatial and temporal data. However, there is still little attention on leveraging aerial robots to interact with trees for sample collection and targeted countermeasure deployment. In this study, we propose platforms and methodology that offer the use of aerial robots in the forests to conduct various tasks including leaf sample collection, visual sensing of forest topology and autonomous sensor placement. With the developed virtual reality (VR) interface, we show that remote environmental sensing, detection of plant pathogens, and sample collection are viable tasks that can be achieved by the proposed platforms. In this context, physical and visual sensing approaches as well as various aerial robots are introduced and discussed for forest applications

FireDrone: multi-environment thermally agnostic aerial robot

Deploying robots in extreme environments reduces risks to human lives. However, robot operating conditions are often limited by environmental factors such as extreme temperatures encountered in fire disasters or polar regions. Especially drones face challenges in carrying thermal management systems protecting vital components, due to limited payload capacity compared to ground robots. Herein, a thermally agnostic aerial robot comprising structural thermally insulating material and a phase change material cooling system, inspired by natural thermal regulation principles, is designed, modelled and experimentally validated. Building on the robot development paradigm of physical artificial intelligence, the concurrent development of materials and design enables the creation of novel physiologically adaptive systems. Polyimide aerogel is applied as one of the main structural materials in the drone's design to adapt the robot's structure and properties to extreme temperatures. Glass fiber reinforcement with silica aerogel particles reduces high-temperature shrinkage and pore structure degradation after exposure to high temperatures and most of the composite aerogel features are preserved. A high technology-readiness-level drone prototype, allowing for operation in a broad range of ambient temperatures, is demonstrated. The proposed technology for thermally agnostic drones may unleash the great potential of aerial robotics in multiple industrial and research applications

Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the Clavicipitaceae reveals dynamics of alkaloid Loci

The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some—including the infamous ergot alkaloids—have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species), a morning-glory symbiont (Periglandula ipomoeae), and a bamboo pathogen (Aciculosporium take), and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories of the epichloae, their protective roles as symbionts, and their associations with the highly speciose and ecologically diverse cool-season grasses

Biopolymer cryogels for transient ecology-drones

Aerial robots can autonomously collect temporal and spatial high-resolution environmental data. This data can be utilized to develop mathematical ecology models to understand the impact of climate change on our habitat. In case of drone 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