The sanding of hidden insulation results in a more reliable method to measure the reception of robotic touch

Researchers from the Northwestern University and the University Tel Aviv of Israel have overcome a major obstacle to the realization of a low -cost solution for an advanced robotic touch. The authors argue that the problem that has hidden in the margins of many articles on touch sensors lies in robotic skin itself.

In the study, inexpensive silicon rubber composites used to make the skin have been observed to host an insulating layer on the upper and lower surfaces, which prevented direct electrical contact between the detection polymer and surveillance surface electrodes, which makes precise and reproducible measurements practically impossible.

With the eliminated error, inexpensive robotic skins could allow robots to imitate human touch, allowing them to detect the curves and the edges of an object, which is necessary to grasp it correctly.

In an article published in the journal Advanced electronic materialsAn interdisciplinary team of researchers who associate electrician engineers with scientists in polymer materials highlights this problem and provides a path to follow with practical steps to validate electrical contacts, which could be obscuring the performance of devices, according to the McCormick School of Engineering in Northwestern.

“Many scientists find it hard to understand their response from the sensor because they bring together the behavior of contacts with the behavior of the sensor material, resulting in incoherent data,” said Grayson.

“It turns out that if you are not aware of this problem, you can publish articles that no one can reproduce. Our work identifies the exact problem, quantifies its extent both microscopically and electrically, and gives a step -by -step focusing manual to solve the problem.”

The rubber which can be used for typical robotic skin, called elastomer, is flexible, light and inexpensive, and when they electrically driven loads like carbon nanotubes are added to the mixture, the resulting composite becomes an ideal candidate for a tactile sensor, whose resistance changes locally when pressed.

But to receive electrical signals, the sensors must be contacted electrically and the researchers have detected a thin insulating layer still present in such composites which could considerably change the behavior of contacts.

Just by tonting the ultra -minor insulation layer, the team was able to obtain a much stronger electrical contact and calibrate the thickness of the insulating layer that is both electrically and microscopic.

“All interesting things happen at the interface,” said the co-author and professor at the University of Tel Aviv Noa Lachman. “This publication not only shows the importance of sensor interfaces, but also the importance of working at the link between two different disciplines: materials science and electrical engineering.

“Material experts suspected the presence of this insulating external layer in driver’s polymer composites for years, but could not understand its electrical effects. Each of us has a piece of the puzzle, but only together can we have the whole situation.”

Robotics in particular can be difficult in part because it requires many types of expertise. The scientist of polymer materials conceiving the functional electronic material for a robot, for example, does not have the same training and the same skills as the electrician engineer whose electronics will process the signals of the sensor. Grayson said the challenge of “contact preparation” was precisely where the conversation on this research had started.

“This is why our collaboration with Tel Aviv is essential – they know the science of materials that we do not know,” said Grayson. “We are counting on them to prepare the materials we are studying, then we take and study the material before returning to help scientists such as Aviv to better characterize their materials.”

Produce new materials – then reproduce them – required consistency in many different variables which are often difficult or even impossible to control. By exposing the question of reproducibility in a large part of the literature on tactile detection, Grayson tests the research community to be held to a higher standard with quality control described in the article.

While awareness of this problem is spreading among researchers, new publications can be more rigorously invoked to advance the field with new capacities.