Image of Electronic Skin
The ACES developed by Asst Prof Tee (far left) and his team responds 1000 times faster than the human sensory nervous system. (Credit: National University of Singapore)

Robots and prosthetic devices may soon have a sense of touch equivalent to, or better than, the human skin with the Asynchronous Coded Electronic Skin (ACES), an artificial nervous system. The new electronic skin system has ultra-high responsiveness and robustness to damage and can be paired with any kind of sensor skin layers.

Drawing inspiration from the human sensory nervous system, the researchers spent a year and a half developing a sensor system that could potentially perform better. While the ACES electronic nervous system detects signals like the human sensor nervous system, unlike the nerve bundles in the human skin, it is made up of a network of sensors connected via a single electrical conductor. It is also unlike existing electronic skins which have interlinked wiring systems that can make them sensitive to damage and difficult to scale up.

ACES can detect touches more than 1,000 times faster than the human sensory nervous system. For example, it is capable of differentiating physical contact between different sensors in less than 60 nanoseconds — the fastest ever achieved for an electronic skin technology — even with large numbers of sensors. ACES-enabled skin can also accurately identify the shape, texture and hardness of objects within 10 ms, 10 times faster than the blinking of an eye. This is enabled by the high fidelity and capture speed of the ACES system.

The ACES platform can also be designed to be highly robust against physical damage, an important property for electronic skins because they come into the frequent physical contact with the environment. Unlike the current system used to interconnect sensors in existing electronic skins, all the sensors in ACES can be connected to a common electrical conductor with each sensor operating independently. This allows ACES-enabled electronic skins to continue functioning as long as there is one connection between the sensor and the conductor, making them less vulnerable to damage.

ACES has a simple wiring system and remarkable responsiveness even with increasing numbers of sensors. These key characteristics will facilitate the scale-up of intelligent electronic skins for artificial intelligence (AI) applications in robots, prosthetic devices, and other human machine interfaces. The team is looking to further apply the ACES platform on advanced robots and prosthetic devices in the next phase of their research.