Robots can feel pain soon? New electronic skin brings human-like reflexes closer to reality

Robots

• City University of Hong Kong develops electronic skin for safer humanoid robots
• Skin detects gentle touch vs harmful force, triggers rapid protective reflexes
• Damaged skin sections can be quickly replaced using magnetic modules

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Researchers at City University of Hong Kong have taken an important step towards making humanoid robots safer and more responsive in real-world environments. The team has developed a new form of electronic skin that can detect touch, distinguish between gentle contact and harmful force, and trigger rapid protective responses that resemble human pain reflexes.

The research, led by engineer Yuyu Gao, focuses on replicating how the human nervous system handles sensory input. In humans, touch and pain are not processed in the same way. Light contact is interpreted and analysed by the brain, while dangerous stimuli often trigger immediate reflexes that bypass conscious thought. The newly developed robotic skin follows a similar principle, allowing robots to react faster and more intelligently to their surroundings.

Unlike traditional robotic skins that rely on simple pressure sensors, this neuromorphic skin converts physical contact into electrical signals that behave like neural pulses. These signals vary depending on the intensity of the pressure applied. A light touch generates a weak signal, while stronger or potentially damaging force produces a much more intense response. This allows the robot to tell the difference between normal interaction and a situation that could cause harm.

The electronic skin is built using four functional layers, each designed to emulate a different aspect of biological nerve pathways. During routine contact, the signals travel to a central processing unit, where they can be used to guide tasks such as gripping objects, adjusting force or interacting safely with humans. This makes the system suitable for delicate operations that require precise tactile feedback.

When pressure crosses a predefined pain threshold, however, the system switches behaviour. Instead of sending information to the main processor, the skin generates a high-voltage pulse that travels directly to the robot’s motors. This bypass triggers an immediate withdrawal movement, closely mirroring how a human instinctively pulls away from something sharp or hot. By avoiding the delay of central processing, reaction times are significantly reduced.

According to the researchers, this reflex-style architecture not only protects the robot from physical damage but also reduces the risk of injury to people and objects nearby. In shared environments such as factories, hospitals or homes, this type of rapid response could be critical for safety and trust.

The system also includes a built-in method for detecting damage to the skin itself. Each sensor unit continuously emits a small electrical signal to indicate that it is functioning correctly. If part of the skin is torn, cut or otherwise damaged, that signal disappears. This allows the robot to pinpoint the exact location of the fault almost instantly, rather than relying on external diagnostics.

While the material does not repair itself, maintenance has been designed to be simple. The skin is made up of magnetic modules that attach like blocks. Damaged sections can be removed and replaced in seconds without dismantling the entire robotic surface, reducing downtime and repair complexity.

The findings were published in the scientific journal PNAS and highlight how closely robotics is beginning to mirror biological systems. As humanoid robots become more common in everyday settings, technologies like this electronic skin could play a key role in making them safer, more adaptive and better suited to working alongside humans.