Research

Omegabot is a small-scale crawling and climbing robot inspired by the inchworm that has simple gait but complex mobility. The robot is fabricated with the Glass fiber composites for the body and coil SMA spring actuators for muscles. An adaptive gripper which is inspired by prolegs of Inchworm was developed for the robot to climb a uneven vertical surface. The flea and flytrap robots are designed based on anatomy and mechanism in real Flea and Flytrap and build with the flexure based composite structure technique like the Omegabot. Flea and Flytrap are fast organisms in nature that exceed performance of ordinary animals. The question was how to utilize the principles in mechanisms of the flea that is very small and the flytrap that is a plant for the robot to generate an extreme speed. Finally, we could build a unique latch mechanism and composite body structure that reproduce their mechanisms. The robotic water strider is developed with abstracting principles on water jumping locomotion of the water striders. The robot was carefully designed to generate a driving force just below the force that break the water surface (surface tension). We learned the novel mechanisms and principle from nature creatures and Bio-inspired design could give solution for the robots and change the common problems.

The Primary advantages of folded robot design are that the inherent accessibility and low cost of the method permits designers to get design feedback early and often via fast prototyping cycles. While prototyping is relatively fast, the complexity of multi-layer articulated designs can be time-consuming and unwieldy to design. I am developing an integrative design methodology to make the design and manufacture of foldable robots more convenient for non-experts.

To build a self-folding Origami structure with high speed and repeatability (folding and unfolding), I employed the torsion SMA wire actuator which can generate torque at a folding line. Single wire is twisted and embedded in the folding line and it folds the sheet rapidly and unfolds by the antagonistic actuator with proper SMA modeling.

Developing the design principles and a method to make the SMA actuator more efficient actuator for the small-scale robot application. In small scale robot, the actuator is limited by the small volume and power performance. The SMA actuator is most suitable candidate for miniaturization of the robot though it has several disadvantages in efficiency and precise control.

The simple design framework for the coil SMA actuator can be applied to different type of actuator such as the torsion SMA actuator which is used in the self-folding Origami.