A 3D Printed Soft Robotic Monolithic Unit for Haptic Feedback Devices

Stroke is a worldwide health problem causing loss of sensory and motor functions. Biofeedback plays a significant role in the rehabilitation process of stroke patients where various haptic feedback methods and devices are used. Such methods and devices can greatly improve the biofeedback provided during the rehabilitation process. This work proposes a soft monolithic haptic feedback device that can be directly manufactured using a low-cost additive manufacturing technology known as fused deposition modelling (FDM) that employ soft and flexible materials with low elastic moduli. A single unit of the soft haptic feedback device proposed was analyzed using finite element modeling (FEM). The experimental mechanical deformation and force output of the device are presented. A conductive resistive material was used to directly 3D print the sensory component of the device that provides force generated by the soft haptic feedback device when it is in direct contact with the human skin. A thermoplastic poly(urethane) (TPU) was employed to 3D print the actuation unit of the soft haptic feedback device.