Proceedings Article | 29 March 2019
KEYWORDS: Robotics, Smart materials, Robots, Sensors, Agriculture, Materials science, Haptic technology, Additive manufacturing, Actuators
As a continuously growing field of robotics, soft robotics is the science and engineering of the robots primarily made of soft materials, components and monolithic active structures such that these soft robots can safely interact with and adapt to their environment better than the robots made of hard components. Soft robotics offers unprecedented solutions for applications involving safe interaction with humans and objects, and manipulating and grasping fragile objects, crops and similar agricultural products. The progress in soft robotics will have a significant impact especially on medical applications such as wearable robots, prosthetic devices, assistive devices, and rehabilitation devices. Robotics research and application community need smart or active or live materials that can change their mechanical, electrical and chemical properties as per the stimuli applied and can be printed into a form/shape with a function to realize soft robots. The progress in soft robotics strongly depends on the progress in materials science and technology.
After briefly describing what characteristics differentiate the field of soft robotics from the conventional hard robotics and significance of smart materials for soft robotics, we will answer the question of where we are in soft robotics to establish prosthetic hands with features which will bring them one step closer to their natural counterparts. The primary feature of such a prosthetic hand should be to interpret and receive the hand user’s intention noninvasively, and equally importantly send sensory feedback about the state of a prosthetic hand to its user noninvasively in order to help “restore normality” for prosthetic hand users. We will also report on the progress we have made in the establishment of a fully 3D printed, low cost, low weight and low foot-print transradial prosthetic hand at our center of excellence, ACES, at University of Wollongong.
Current prosthetic hands are heavy and expensive with many degrees of freedom to control, requiring a significant amount of battery power. Further, they do not contain sensory or haptic feedback, making their acceptance physically and sensationally worse. With recent progress in soft smart materials and additive manufacturing techniques, we disclose a low cost, low power, low weight, low foot-print prosthetic hand equipped with touch/pressure sensors and strain sensors to provide life like sensory feedback to its users. This soft hand with programmable compliance is designed to have a monolithic topology (i.e. one-piece geometry) with its finger joints simulating motion of the natural fingers such that the hand conforms to the shape of the object it grasps. The hand is fabricated such that it does not require any assembly; ready to be used straight from the fabrication process. It is articulated with a limited number of actuators to provide adaptive grasping ability and address significant deficiencies of the conventional prosthetic hands made of rigid joints and links.
