The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project will use shape-morphing electroactive polymers (EAPs), also known as synthetic muscle, to provide for a streamlined and very life-like way of configuring motion, which doesn't require motors, pulleys, gears, or cables like traditional mechanical based motion. The power to operate these EAPs is easily provided by electric input, including using off the shelf commercially available batteries. In addition to the focus of this proposal on adjustable liners, these EAPs could mend the gap between form and function for life-like prostheses. As impact attenuating and sensing materials, these EAPs could be developed to offer solutions for protective equipment and provide life-like motion and control for robotics. This proposal is focused on transforming the standard of care for people who have lost limbs or were born without fully developed limbs. <br/><br/>The proposed project promises to transform the standard of care for people who have lost limbs or were born without fully developed limbs. Amputees using mechanically driven prostheses often experience increasing pain, as well as risk of skin breakdown and severe infections, even over the course of daily use, due to normal anatomical changes in the limb that are not accommodated by the static, rigid socket of their prosthetic device. Typically, most amputees' residual limbs shrink over the course of any given day, much like peoples' foot size changes from morning to evening. This proposed work aims to resolve the inadequacies of current prosthetic socket fit by using flexible pads of EAP based synthetic muscle, built into prosthetic liners, to automatically respond to changes in patient anatomy and ensure a continuously proper socket fit throughout the day. With the additional ability to sense pressure, these EAPs can also serve as a diagnostic tool to prevent skin breakdown. The prosthetic device and human should move as one, effortlessly and naturally. This proposal will develop self-adjusting prosthetic liners that responds to residual limb changes, maintaining a comfortable dynamic perfect fit throughout the day, to allow the patient to easily and comfortably engage in an active lifestyle.