Shaking hands with a robot

Jon Lawson

Will the future of humanity resemble the robot-filled societies seen in science fiction? In fact, human-like robots are much closer to becoming a reality than you may think. Thanks to nanotube-based sensors, electronic skin can detect touch just like a human.

Imagine a human-like robot in your daily life. It interacts with your children and pets, serves you at the supermarket, and even if necessary, extracts your tooth or performs a more complex operation. It is now possible, as scientists have finally found the answer on how to give robots human-like tactile senses. While they cannot feel as we do, robots are now able to detect their environment almost as well as a human.

Osaka Prefecture University (OPU) is already known for robots that are human-like in appearance, Erica and Ibuki. Another research group led by Prof. Kuniharu Takei has accepted a challenge that is probably even more ambitious: to make electronic skin that senses in the same way as a human’s.

We can gently stroke a puppy or firmly shake someone’s hand, but today’s robots are unable to distinguish these types of touch. The absence of simultaneous monitoring of tactile pressure and temperature change is the main obstacle, according to Takei. Creating elastic, flexible soft robotic hands was the barrier for the integration of multiple sensors. OPU researchers have for the first time successfully integrated multiple nanotube-based tactile and temperature sensors into a pneumatic balloon-based soft robotic hand without sensitivity to bending of the structure of the hand.

An array of four tactile sensors and one temperature sensor based on highly conductive single wall carbon nanotubes can monitor sliding or slipping movements of an object from a robotic hand by detecting the time delay of the tactile force. This provides real-time feedback so that the robotic hand can adjust the actuation force to prevent dropping the object.

Furthermore, a robotic hand with nanotube-based sensors can detect the tactile force and temperature generated by a human hand, while each sensor measures the tactile force generated by a human finger independently.

The next challenge scientists face to bring truly human-like robots to life is expanding the quantity of sensors in e-skin, as well as further developing signal-processing and signal-feedback systems.