The key to Ras Labs’ FingerTip™ sense of touch comes from our compliant electroactive polymers (EAPs). Ras Labs makes Synthetic Muscle™, which is a patented class of EAP based materials and actuators that sense pressure (gentle touch to high impact), controllably contract and expand at low voltage (battery levels), and attenuate force.1,2 Synthetic Muscle™ is a durable manmade material capable of life-like tactile sensing feedback and biomimetic motion, and able to withstand harsh environments: extreme temperatures, pressures, radiation, and areas with contagions that have no cure. Ras Labs’ EAPs are scalable and can be made in a variety of shapes, sizes, and thickness. This is a strong material platform business that can lead to many applications; however, our current focus is providing human-like touch and feedback to robotic grippers and end of arm tooling (EOAT).
Ras Labs’ FingerTip™ sensors have been integrated into traditional marketplace grippers. These sensors generate immediate feedback at the first point of contact. Because these pads provide a soft, compliant interface (they feel like human fingertips), the point of contact is gentle, yet also firm. These sensors also detect the change in pressure location on its surface, making it possible to detect and prevent slippage by then adjusting the grip strength, without stutter, due to both feedback and the pad’s compliance. The soft gentle nature of our FingerTip™ sensors naturally hold gripped objects, even ripe fruit, with no droppage, no slippage, and no damage.
The sensitivity of our sensor's electroactive polymer showcases a unique capability. Incredibly, our FingerTip™ sensor has the ability to detect heartbeat pulses when a human holds the sensor against their wrist or fingers. Even more, the sensor can distinguish between the 4 steps of cardiac conduction within one heartbeat. These soft sensors are extremely sensitive, with a broad pressure range from at least 0.05 N up to 50 N, with 1 mm resolution. Human touch is around 0.1 N pressure sensitivity.3 We were aiming for human tactile touch and we have surpassed this. Ras Labs’ soft compliant FingerTip™ sensors are robust (1,000,000+ cycles with full functionality), vastly sensitive, and have a wide pressure range.
Ras Labs has the power to replicate human grasp. The combination of Ras Labs’ EAP based Synthetic Muscle™ shape-morphing and FingerTip™ sensing promises the potential for robotic grippers and prosthetic hands with human hand-like dexterous control and tactile touch sensing. This is expected to transform robotics, whether it is for agriculture, manufacturing, or E-commerce, as well as for collaborative robotics to allow humans and robots to intuitively work safely and effectively together.
1. L. Rasmussen, Editor, “Smart Materials: Considerations in Space and on Earth,” Springer, GmbH & Co. KG, pre-publication © 2021.
2. L. Rasmussen, Editor, “Electroactivity in Polymeric Materials,” Springer-Verlag, GmbH & Co. KG © 2012.
3. Patel B., Synthetic Skin Sensitive to the Lightest Touch, https://spectrum.ieee.org/biomedical/bionics/synthetic-skin-sensitive-to-the-lightest-touch © 2010.