Our PapillArray sensor
Our sensor is a soft, silicone array, similar to a human finger pad, that can measure 3D deflection, 3D force and 3D vibration at each array element, as well as measuring important emergent properties such as torque, incipient slip and friction – essential tactile parameters for robotic dexterity.
Novel optical technique
The principle of operation of our sensors is our patented novel optical sensing method.
A cavity is created Inside each soft pillar of the sensor. LEDs, a reflector disk, an aperture and four photodiodes form a camera obscura inside the cavity.
The infrared LEDs flood the pillar cavity with light.
The diffuse reflector, at the top of the cavity, reflects the light down towards the aperture.
Below the aperture, a light spot is projected onto the four photodiodes.
The light intensity signals measured by the four photodiodes are used to infer the displacement and force applied to the pillar tip.
Our technology has two competitive advantages over other tactile, force, and torque sensing technologies.
We can estimate friction (or traction, as a corollary). There is no other sensor that can do this, yet it is a vital tactile parameter if an adequate and efficient grip force is to be applied. No other tactile sensing technology can enable gripping with just the right amount of force. Our incipient slip detection and friction measurement can enable secure and efficient robotic gripping, which provides an economic benefit to users of robotic grippers by reducing damage to components/merchandise (by dropping/crushing objects) as well as lower power consumption, which is particularly important in mobile robotics.
We can sense all other important tactile properties, whereas other sensors can only sense a subset of these properties. We can sense 3D displacement and 3D force at each element, which helps detect incipient slip. We can sense vibration to a very high frequency, which also helps in detecting slip (used to estimate friction/traction) and facilitates recognition of surface texture and material type. We can also sense global forces and torques, obviating the need for additional expensive force/torque sensors.
ENABLING ROBOTIC DEXTERITY
A robotic gripper with our sensors integrated on the fingertips would be able to grasp objects it has never encountered before with an optimal grip force (i.e., safely and securely), irrespective of the object weight, size and friction without additional inputs or programming. This is precisely what is required for object manipulation in unstructured environments, which has traditionally been a challenge to automate. Our sensors will also enable the automation of processes that could not previously be reliably automated, such as handling of unfamiliar objects, and fully collaborative material handling.
Robotic grippers endowed with our tactile sensors could assist in numerous material handling tasks as well as enable custom manufacturing and manufacturing at a low volume where automation is particularly challenging.