Leveraging the unique mechanics of controllable gecko-inspired adhesives, we are able to grasp objects without applying a normal force. Instead, we rely only on the contact area between the gripper and the object.
While numerous variations of synthetic gecko-inspired adhesives have been shown to provide strong, reusable adhesion, we focused on scaling this adhesion to the sizes needed to support a human. With special attention to load sharing, we were able to climb a glass wall with a hand-sized area of synthetic adhesive.
Hawkes E.W., Eason E.V., Christensen .DL., Cutkosky M.R. 2015 "Human climbing with efficiently scaled gecko-inspired dry adhesives." Journal of the Royal Society Interface 12: 20140675. Online Preprint
Instead of inflating our artificial muscle to cause contraction as traditional pneumatic artificial muscles (PAMs) do, we inflate to lengthen, or relax, the muscle. In doing so, we store elastic energy that can powerfully released on command. This scheme of actuation also allows for unprecedented strain rates from our actuators.
We developed two small-scale robotic climbers that can hoist many times their weight. One is 9 g and is powered by a single servo motor, using an inchworm gait to move up the wall while carrying over 1 kg (>100x bodyweight). The second is a tiny 20 mg climbing, powered by SMA that can hoist 500 mg.
We designed and built a system that can control two outputs with a single motor. The device relies on a clutch that is controlled by the motor speed and position.
Hawkes, E.W., Christensen, D.L., Pope, M.T., and Cutkosky, M.R., "One Motor, Two Degrees of Freedom through Dynamic Response Switching." Robotics and Automation Letters.Published online February 15, 2016. http://dx.doi.org/10.1109/LRA.2016.2526066
Soft Exomuscles for Rehabilitation
We are developing a soft exoskeleton, or rather an exomuscle, to help offload certain muscles of the upper body to aid in Activities of Daily Living (ADLs) for stroke patients.
Assistive Device for Decreasing the Cost of Running Locomotion
We are investigating methods of reducing the cost of running through wearable assistive devices.
We are developing a new type of soft robot that exhibits the behavior of apical extension. This form of movement, growth from the tip, is found across kingdoms and length scales, from vines to tiny cells such as fungal hyphae, pollen tubes, and root hairs, to growing neurons.
We are working with Neurosurgeons and Interventional Neuroradiologists at Stanford Hospital to design new catheters for accessing challenging physiology in the brain. Images: Dr. Jeremy Heit.