Popup Arrays for Large Space-Borne Apertures

Large apertures in space are critical for high-power and high-bandwidth applications spanning wireless power transfer (WPT) and communication, however progress on this front is stunted by the geometric limitations of rocket flight. Here, we present a light and flexible 10GHz array, which is composed of dipole antennas co-cured to a glass-fiber composite. The arrays are designed to dynamically conform to new shapes and to be flexible enough to fold completely flat, coil, and pop back up upon deployment. The design was chosen to be amenable to scalable, automated manufacturing - a requirement for the massive production necessary for large apertures. Moreover, the arrays passed the standard gamut of required space-qualification testing: the antennas can survive mechanical stress, extreme temperatures, high-frequency temperature cycling, and prolonged stowage in the flattened configuration. The elements exhibit excellent electromagnetic performance - with a return ratio better than -10dB over a bandwidth of 1.5GHz and a single lobe half-power beam width of greater than $110^\circ$ suitable for broad range beamforming and with excellent manufacturing consistency. Moreover, its mechanical durability vis-a-vis extreme temperatures and protracted stowage lends itself to demanding space applications. This lightweight and scalable array is equipped to serve a host of new space-based radio-frequency technologies and applications which leverage large, stowable and durable array apertures.Comment: 12 pages, 21 figure

Transient bio-inspired gliders with embodied humidity responsive actuators for environmental sensing

Collecting temporal and spatial high-resolution environmental data can guide studies in environmental sciences to gain insights in ecological processes. The utilization of automated robotic systems to collect these types of data can maximize accuracy, resilience, and deployment rate. Furthermore, it reduces the risk to researchers deploying sensors in inaccessible environments and can significantly increase the cost-effectiveness of such studies. The introduction of transient robotic systems featuring embodied environmental sensors pushes towards building a digital ecology, while introducing only minimal disturbance to the environment. Transient robots made from fully biodegradable and non-fossil based materials, do not develop into hazardous e-waste at the end of their lifetime and can thus enable a broader adoption for environmental sensing in the real world. In this work, our approach towards the design of transient robots includes the integration of humidity-responsive materials in a glider, which is inspired by the Alsomitra macrocarpa seed. The design space of these gliders is explored and their behavior studied numerically, which allows us to make predictions on their flight characteristics. Results are validated against experiments, which show two different gliding behaviors, that can help improve the spread of the sensors. By tailoring the Cellulose-Gelatin composition of the humidity actuator, self-folding systems for selective rainwater exposure can be designed. The pH sensing layer, protected by the actuator, provides visual feedback on the pH of the rainwater. The presented methods can guide further concepts developing transient aerial robotic systems for sustainable, environmental monitoring

Transient bio-inspired gliders with embodied humidity responsive actuators for environmental sensing

Collecting temporal and spatial high-resolution environmental data can guide studies in environmental sciences to gain insights in ecological processes. The utilization of automated robotic systems to collect these types of data can maximize accuracy, resilience, and deployment rate. Furthermore, it reduces the risk to researchers deploying sensors in inaccessible environments and can significantly increase the cost-effectiveness of such studies. The introduction of transient robotic systems featuring embodied environmental sensors pushes towards building a digital ecology, while introducing only minimal disturbance to the environment. Transient robots made from fully biodegradable and non-fossil based materials, do not develop into hazardous e-waste at the end of their lifetime and can thus enable a broader adoption for environmental sensing in the real world. In this work, our approach towards the design of transient robots includes the integration of humidity-responsive materials in a glider, which is inspired by the Alsomitra macrocarpa seed. The design space of these gliders is explored and their behavior studied numerically, which allows us to make predictions on their flight characteristics. Results are validated against experiments, which show two different gliding behaviors, that can help improve the spread of the sensors. By tailoring the Cellulose-Gelatin composition of the humidity actuator, self-folding systems for selective rainwater exposure can be designed. The pH sensing layer, protected by the actuator, provides visual feedback on the pH of the rainwater. The presented methods can guide further concepts developing transient aerial robotic systems for sustainable, environmental monitoring.ISSN:2296-914

A Soft Robotic Morphing Wing for Unmanned Underwater Vehicles

Actuators based on soft elastomers offer significant advantages to the field of robotics, providing greater adaptability, improving collision resilience, and enabling shape-morphing. Thus, soft fluidic actuators have seen an expansion in their fields of application. Closed-cycle hydraulic systems are pressure agnostic, enabling their deployment in extremely high-pressure conditions, such as deep-sea environments. However, soft actuators have not been widely adopted on unmanned underwater vehicle control surfaces for deep-sea exploration due to their unpredictable hydrodynamic behavior when camber-morphing is applied. This study presents the design and characterization of a soft wing and investigates its feasibility for integration into an underwater glider. It is found that the morphing wing enables the glider to adjust the lift-to-drag ratio to adapt to different flow conditions. At the operational angle of attack of 12.5 degrees, the lift-to-drag ratio ranges from -70% to +10% compared to a rigid version. Furthermore, it reduces the need for internal moving parts and increases maneuverability. The findings lay the groundwork for the real-world deployment of soft robotic principles capable of outperforming existing rigid systems. With the herein-described methods, soft morphing capabilities can be enabled on other vehicles.ISSN:2640-456