Engineers From Columbia University Design a Robotic Finger with a Sense of Touch
The robotic finger can localize touch with very high precision over a large, multi-curved surface much like its human counterpart.
Robots have several advantages over us humans — they’re stronger, more efficient at handling certain tasks, and have greater endurance. That said, they are limited in their senses, including the sense of touch. A team of engineers from Columbia University, however, is working to solve the issue by giving robots the ability to ‘feel’ objects by using light.
The team designed a robotic finger that features a 3D-printed frame outfitted with 32 photodiodes and 30 LEDs encased in a flexible silicone skin, which keeps outside light from entering. The ability to feel is done when the robotic finger touches an object, and its silicone skin deforms, limiting the amount of light emitted from the LEDs detected by the photodiodes. A machine learning system uses that light information to determine where contact is being made, and the amount of intensity and pressure at that location.
Measuring the amount of light traveling from every LED to the diodes, the engineers were able to acquire nearly 1,000 signals, with each containing information on the contact that was made. As light can bounce around inside the curved silicone skin, the signals can cover complex 3D shapes, such as a fingertip.
Mechanical engineering and computer science assistant professor Matei Ciocarlie states, “The human finger provides incredibly rich contact information — more than 400 tiny touch sensors in every square centimeter of skin! That was the model that pushed us to try and get as much data as possible from our finger. It was critical to be sure all contacts on all sides of the finger were covered — we essentially built a tactile robot finger with no blind spots.”
The engineers state that they created the robotic finger to be incorporated into robotic hands, which they claim is easy as it doesn’t require any off-board electronics, and only needs 14 wires to transmit those signals to a connected hand. They have already built a pair of robotic hands that use the special fingers, and are looking to demonstrate dexterous manipulation abilities with further development.