Today's robots can understand human speech, but are unable to feel human touch.
But all that may be a thing of the past with two Indian-born scientists at the University of Nebraska, Lincoln having developed what they claim is a small film that can mimic the sensitivity of a human finger.
This they say will become useful in the next generation of robots and in automated tools used for microsurgery.
One of the first senses that humans develop, touch is all about relaying information about the surface of an object, and the amount of pressure needed in order to grasp it, but scientists faced problems of rigidity and durability during previous experiments with robots on touch.
When constructed out of hard materials such as silicon, they were not able to contour to the robotic 'hand', while the daily wear and tear of touching also tended to bend and scratch the delicate materials.
Professor Ravi Saraf, a graduate from the Indian Institute of Technology, Kanpur, and his colleague Vivek Maheshwari, recently unveiled their new sensor film at this week's issue of Science.
The film is about 100 nanometres thick, roughly 1,000 times thinner than standard office paper. Built like a sandwich of alternating layers of gold and cadmium sulphide nanoparticles, each separated by insulating polymer sheets just 2 or 3 nanometres thick, they are something like a "human skin" for robotic arms.
Researchers say the sensor can detect tiny surface details with a pressure of 9 kilopascals, similar to that used by human fingers to feel and pick up things.
It can also sense letters and shapes on a penny, as compared with a conventional microscope image, and distinguish features as small as 40 micrometres wide on a surface, just like a human finger can.
Previous sensors could only detect in the millimetre range, they said.
Experts however, opine that it may be some time before such sensors are used in medical studies.
