Carnegie Mellon University

Soft Artificial Skin Sensors

We are focusing on designing and manufacturing soft artificial skin sensors for various applications by implementing novel fabrication methods conbined with additive manufacturing, micromachining, and shape deposition manufacturing. We recently developed soft artificial skin sensors that detect contact pressure and multi-axis strains and shear forces. These soft sensors are made of highly stretchable silicone elastomer with embedded microchannels filled with conductive liquids, such as liquid metals and ionic liquids.

Soft Artificial Muscle Actuators

We are also developing soft artificial muscle actuators. Examples are miniaturized pneumatic artificial muscles for use in soft exoskeleton suits that not only provide active assistance but also increase physical endurance of the wearer. The hyperelasticity of the skin and muscle materials make the device easily wearable and conformable to complicated 3-D human bodies. The artificial muscles also were designed to include embedded sensing elements that can detect the contraction of the muscle in real-time.

Soft Robots

As an application of the above soft sensors and actuators, we are developing soft wearable robots for human rehabilitation The design of the device was inspired by the biomechanics of a human body, mimicking not only the morphology but also the functionality of the biological muscle-tendon-ligament architecture. In contrast to prior exoskeletons, our biomimetic design allows a completely soft structure that provides active support and assistance without adding physical constraints to the wearer. These devices can be powered by either pneumatic or electromagnetic actuation. They are also equipped with various embedded soft sensors for measuring the biomechanics of the wearer. Ultimately, we envision a system that not only provides physical support to improve mobility but also increases safety and stability, while enhancing muscle usage and rehabilitation.

Smart Robotic Structures

We also have focused on designing biologically inspired robots with embedded optical sensors for medical applications. Our work on Force Sensing Robot Fingers proved that exoskeletal robot structures with embedded fiber optics could provide an accurate and physically robust solution in detecting small contact forces. As an enabling technology, we developed a novel manufacturing method that allowed us to create hollow hexagonal mesh structures with embedded fiber optic sensors. In addition to sensitivity and robustness, one of the advantages of fiber optic sensors is immunity to electromagnetic interference. Thus, our subsequent work focused on implementing fiber optics to biomedical devices that could be used in extreme environments such as magnetic resonance imaging (MRI) systems: MRI-Compatible Shape Sensing Needle with embedded fiber optics.