The study could allow cheap robotic skins to mimic human touch.
Researchers have made a breakthrough that could pave the way for affordable, highly sensitive robotic touch.
A team from Northwestern University and Israel’s Tel Aviv University discovered that a hidden flaw in widely used silicone rubber composites—insulating layers on the surface—was blocking accurate electrical sensing in robotic skin.
By identifying and addressing this issue, the team unlocked the potential for low-cost robotic skins to deliver precise, human-like touch.
According to the team, the advancement could help robots better detect shapes, curves, and edges, dramatically improving their ability to grasp and handle objects.
Hidden flaw in robotic touch sensors
The team’s study unearthed a hidden flaw in conductive elastomer composites—materials widely used in flexible sensors for robotics and wearable electronics. Their study reveals that an ultrathin insulating layer forms on the surface of these composites during production, significantly affecting the accuracy and reliability of sensor performance.
Electrical engineers and polymer materials scientists worked to address a long-standing problem: inconsistent and irreproducible sensor data caused by poor electrical contact preparation.
According to researchers, the problem stems from researchers not distinguishing between the behavior of the sensor material and the electrical contacts. “A lot of scientists misunderstand their sensor response because they lump together the behavior of the contacts with the behavior of the sensor material,” said Matthew Grayson, a professor of electrical and computer engineering at Northwestern’s McCormick School of Engineering, in a statement.
The researchers achieved stronger and more reliable electrical contact by sanding down this insulating layer. They also developed a calibration method to measure the thickness of the layer both electrically and microscopically, offering a new troubleshooting approach that other researchers can follow.
Cross-disciplinary discovery
The breakthrough was only possible through close collaboration between disciplines. Researchers emphasized the importance of understanding the interface where materials meet electronics. “All interesting things happen at the interface. Each of us has one piece of the puzzle, but only together can we get the whole picture,” said Noa Lachman, professor in the Department of Materials Science at Tel Aviv University, in a statement.
This challenge is especially prominent in robotics, where integrating diverse components designed by experts from different fields makes reproducibility difficult. Researchers say materials scientists focus on creating new composites, but electrical engineers handle how those materials are wired into functioning devices. The two skill sets don’t always overlap, leading to miscommunication and inconsistent results.
RECOMMENDED ARTICLES
Electrical characterization of the conductivity and thickness of the insulating surface layer.
Grayson credits the collaboration with Tel Aviv University as essential. “They know the materials science that we don’t know. We rely on them to prepare the materials, and we help them understand the electrical behavior of those materials,” said the researcher in a statement.
The study serves as a call to action for the broader research community to adopt more rigorous testing and validation standards. By raising awareness of the impact of contact preparation on sensor performance, the team hopes to ensure that future research in touch sensing and flexible electronics is reliable and reproducible.
The details of the team’s study were published in the journal Advanced Electronic Materials.
Jijo Malayil Jijo is an automotive and business journalist based in India. Armed with a BA in History (Honors) from St. Stephen's College, Delhi University, and a PG diploma in Journalism from the Indian Institute of Mass Communication, Delhi, he has worked for news agencies, national newspapers, and automotive magazines. In his spare time, he likes to go off-roading, engage in political discourse, travel, and teach languages.
