Researchers in China have built a neuromorphic robotic electronic skin that allows humanoid robots to sense touch, detect injury, and respond to harmful contact with rapid, reflex-like movements inspired by the human nervous system.

The development addresses a long-standing limitation in robotics. When humans touch something dangerously hot or sharp, sensory nerves send signals directly to the spinal cord, triggering an almost instantaneous withdrawal before the brain fully processes the pain.

This reflexive response helps prevent serious injury.

Humanoid robots, however, typically rely on centralized processing. Sensor data must be transmitted to a central processing unit, analyzed, and then converted into motor commands.

 Even small delays in this process can result in damage, especially as robots increasingly operate around people.

As robots move out of controlled industrial settings and into homes, hospitals, and public spaces, researchers argue that they need more instinctive ways to interact with their environment.

The newly developed neuromorphic robotic e-skin is designed to give machines that capability.

Beyond simple touch

Most existing robotic skins function as pressure sensors, detecting contact without understanding its severity.

They can register that something has touched the robot but cannot determine whether the interaction is potentially harmful.

The neuromorphic robotic e-skin, or NRE-skin, goes further by mimicking how biological skin processes sensory information.

It uses a hierarchical, neural-inspired architecture that converts tactile inputs into electrical pulse trains similar to signals transmitted by human nerves.

The skin is built from four layers. The outermost layer acts as a protective surface similar to human epidermis.

Beneath it are sensors and circuits that behave like sensory nerves, constantly monitoring pressure, force, and structural integrity.

Even when untouched, the skin sends periodic electrical pulses to the robot’s central processor, signaling that the system is functioning normally.

If the skin is cut or damaged, these pulses stop, allowing the robot to detect the injury and identify its location.

Reflexes without thinking

When contact occurs, the skin generates electrical spikes that encode information about the applied pressure. Under normal conditions, these signals are routed to the central processor for interpretation.

However, when the force exceeds a preset threshold indicating potential pain or damage, the system responds differently.

A high-voltage signal is sent directly to the robot’s motors, bypassing the central processor and triggering an immediate reflex, such as pulling an arm away.

“Our neuromorphic robotic e-skin features hierarchical, neural-inspired architecture enabling high-resolution touch sensing, active pain and injury detection with local reflexes, and modular quick-release repair,” wrote the researchers.

“This design significantly improves robotic touch, safety, and intuitive human–robot interaction for empathetic service robots.”

The skin is also designed for rapid maintenance. It consists of magnetic, modular patches that can be quickly detached and replaced, allowing damaged sections to be repaired in seconds rather than requiring extensive servicing.

The research team is now working to improve the system’s sensitivity so it can accurately process multiple simultaneous touch points, a key requirement for robots operating in complex, unpredictable human environments, according to the Proceedings of the National Academy of Sciences.

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