SBIR Phase II: Human Like Robotic Grippers Using Electroactive Polymers

Ras Labs, Inc., Boston MA

Investigators

Abstract

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase II project will be the development of a durable artificial material capable of life-like motion, contracting and expanding like human muscle when controlled by low voltage (12-volt batteries). This material also will replicate human grasp by sensing mechanical pressure across a dynamic range, from gentle touch to high impact. The initial application for this material will be to give tactile sensing to fingertips of robotic grippers. Existing actuators cannot provide streamlined expansion and contraction to manage a good grip while dynamically sensing grip pressure. As an extension to the robotic gripper, this material could provide a lightweight, intuitively easy-to-operate prosthetic hand. Other applications include creating pads for prosthetic sockets to maintain perfect fit; padded liners in football and workplace helmets to absorb forces and communicate impact frequency and severity; shoe inserts for athletic and therapeutic footwear absorbing force attenuation, measuring step frequency, and measuring foot positioning; adjustable lumbar support for seats; switchless consoles for the cockpit, armrests, and dashboards of automobiles; and many others. This SBIR Phase II project will advance robotic grippers by adding a material with sensing capability, with implications for prosthetic hands and other applications. In robotic grippers and prosthetic hands, there is a trade-off between strength and dexterity; furthermore, the sensory perception has not yet been well developed. For grippers, initial gentle pressure has been absent from grip processes, inhibiting handling of delicate objects. The materials under development are shape-morphing and extremely sensitive as pressure sensors. The research objectives and methods/approaches of this project are to: 1) advance the actuation speed and durability of these materials through synthetic and architectural strategies; 2) characterize the speed and detectable pressures through oscilloscopic analysis and amplification circuitry; 3) tie the shape-morphing and sensing attributes together through controlled feedback loop(s) into off-the-shelf grippers, using robust user-friendly electronics; 4) determine durability through long-term cycle testing of contraction/expansion cycles and typically encountered grip pressures (millions of cycles for each test method); and 5) produce sophisticated robotic grippers with tactile-like touch and compare the strength and dexterity with those of the human hand. The goals and scope of this project are to optimize both the shape-morphing and sensing features of these materials and use biomimetic design, particularly around the pincer grip and anatomy of the first and second digits (thumb and index finger), with the anticipated result of replicating human grasp. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.