Inertial Sensing and Flight Control in Hawk-moth Manduca Sexta
(Collaboration with University of Washington)
Insect wings act not simply as actuators, generating the forces necessary for flight, but also act as sensory structures that provide rapid feedback for stable flight control. In this project we use FEM simulations to understand the spatial and temporal pattern of strain over the wing during normal and disturbed flight. When surpassing a threshold, the local strains spark neurons which provides feedback for agile flight.
The goal is to understand the effect of various structural components such as stiffness and damping on the inertial sensing of insect wings, Manduca Sexta in particular. The results will help efficient placement of bioinspired strain sensors over wings of unmanned aerial vehicles for agile flight.
Modeling Bioinspired Strain Sensors for Optimized Designs
Flying organisms have a variety of sensors that assist in flight: vision, strain, flow, and inertial. Biologists have demonstrated that strain sensors found on the wings of the moth, called campaniform sensilla, inform the insect of aerodynamic as well as inertial forces through proprioception. With the goal of achieving fast and efficient sensing as observed in nature, our team at Microrobotics Lab has designed a bioinspired strain sensor that can achieve variety of range and resolutions. In this project, FEM simulations are used to regulate and optimize the design of this sensors for further applications.
Design and Fabrication of NiTi-based Actuators with 3D-Printed Layers for MicroRobotic Applications
Actuation is a huge challenge at small size scales. This project focused on using thin films of NiTi alloys along with microscale 3D printing to engineer reasonably efficient actuators with high work densities.
We fabricated first sputtered thin-film NiTi actuators combined with direct 3D printing of polymeric structures, studied strategies to reduce the energy required for actuation of them by architecting the 3D-printed passive layer and pulsing the input current, and eventually scaled them up for use in mesoscale systems.
Instability-Induced Rapid Shape Change in Photo-Responsive Materials
(Collaboration with University of Pittsburgh)
For a soft system to be useful in wearables and robotics, its essential components (processing, actuation, power) must be fully integrated and embedded within its own structure. But this integration comes with significant trade-offs. A tethered connection to support pneumatic or electrical hardware, or bulky on-board components such as batteries, microprocessors, pumps or motors in untethered systems, which make them hard to be scalable, are a few examples. On the other hand the fully soft and untethered robots can be made of material like light-responsive LCPs but this group usually have very limited functionality.
In this work we address the problem of functionality in systems made out of very thin LCP films by exploring the combination of geometry and microstructure, and proposing configurations that utilize instability, contrary to the common perception.