Robots are the trendsetters now..!!! They are everywhere, in our homes, schools, and industries. Even the experts agree that they are here to stay. But have you ever guessed what the most difficult thing is for a robot? The answer is picking up things. Robots are equipped with several types of grippers to manage products like cans on an assembly line, they are unable to differentiate between items of differing shapes, sizes, and harnesses. Even the most advanced robots have a limitation when it comes to picking up an object. Humans use vision, sensory, and motor skill to do such tasks. In the case of robots, cameras, actuators, and motors can help, but a sensory system that can provide robots with higher dexterity and tactile feedback would be revolutionary.
The University of Bristol researchers believe they have found a solution: 3D-printed fingertips that can help robots “feel” what they’re engaging with. The method, revealed in two new studies published on Wednesday in the Journal of the Royal Society Interface, might be the difference between machines beating humans at virtual chess and machines picking up and maneuvering real chess pieces.
Humans detect touch through nerve endings in the skin known as “mechano receptors,” which send information to our brains such as touch, pressure, and form. The most sensitive area in the top layer of the dermis (the tissue just beneath the skin’s surface) is non-hairy areas like the palms, lips, and, of course, the fingertips. Mechano receptors are one type of nerve ending in the somatosensory system, which regulates our sense of touch. Thermo receptors (which detect temperature), pain receptors, and proprietorship are examples of other receptors (which aid in the perception of bodily parts in relation to one another).
Clearly, replicating this complex network of nerves in a prosthetic is a difficult task. Lepora’s team employed 3D-printed mesh with pin-like papillae—basically, small bumps that protrude from the organ, like the ones on your tongue—on the underside of the “skin” to stimulate mechano receptors in the human fingertip. The goal was to replicate the dermal papillae found in humans between the outer epidermal and inner dermal layers of skin. The protrusions were generated using a sophisticated 3D printer that blended hard and soft elements to build receptors resembling our own biology.
What about testing the fake fingertip? Lepora’s team looked back to previous research published in the Journal of Neurophysiology in 1981. Two scientists plotted electrical recordings from human mechanic receptors in the paper to evaluate their tactile spatial resolution—basically, their ability to recognize a set of conventional ridged forms. Le pora’s team compared its 3D-printed prosthetic fingertip to the identical ridged forms and discovered a very close match to the neuronal data from the 1981 experiment.
The artificial fingertip, on the other hand, is less sensitive to fine detail than a human fingertip. This, according to Le pora, is because 3D-printed skin is thicker than natural skin. As a result, the next step for the team will be to go headfirst into creating more lifelike artificial skin.
Who knows? If it can pick up the queen, we might have a robotic chess Grand master one day.
