Prosthetics are becoming increasingly prevalent in a world where day-to-day actions are often limited to those without disabilities. Bridging this gap, NeurAlbertaTech is currently building an electroencephalogram and electromyography (EEG/EMG)-controlled prosthetic hand from scratch.

For the mechanical side of this prototype, parts will be 3D printed to promote customizability and affordability. The 3D models will also be easy to replicate, promoting accessibility in prosthetics and rehabilitation products. In terms of functionality, the hand would offer flexibility in individual finger movements and wrist rotation. Prototyping includes:
• Research and development of preliminary 3D designs
• 3D printing parts using PLA, ABS, PETG, and TPU
• Testing of prototype by integrating hardware and software together

Since sensory feedback from the hand is absent in most prostheses, an artificial method to restore this sense is crucial in performing day to day tasks such as grasping objects. Using a custom embedded flex sensor made from Velostat and Ecoflex, preliminary tests have been run consisting of:
• 3D printing PLA/ABS molds for casting
• The casting process which includes a layer of Ecoflex, a Velostat sheet, then another layer of Ecoflex
• Curing the Ecoflex in a vacuum chamber

Connecting the exposed Velostat tabs to an Arduino which routes it to a small vibration motor for sensory feedback. The goal of this test is to provide a Proof of Concept (PoC) for a feedback system within the prosthetic hand. With the Velostat layer acting as an electronic skin for the prosthesis, it should be sensitive to changes in pressure and other tactile sensations. Through the Velostat’s ability to change resistance based on applied pressure, differing pressures can be distinguished by Arduino as differing currents. This way, the hand would be able to relay sensory information from the Velostat to the user, restoring their both sensory and motor function.