A research team from the National University of Singapore (NUS) has announced that it has designed a foam-like material that can be described as “intelligent foam”. It would allow robots to better perceive physical contact, and thus, to interact more easily with their environment to detect an object or detect the presence of an individual. For the authors, AiFoam would be a further step towards potentially equipping robots with the five senses of human beings.

A study to design an artificially innervated synthetic material

Hongchen Guo, Yu Jun Tan, Ge Chen, Zifeng Wang, Glenys Jocelin Susanto, Hian Hian See, Zijie Yang, Zi Wei Lim, Le Yang and Benjamin C. K. Tee are the ten authors of the publication referring to the research project that led to the creation of this synthetic material called “intelligent foam” and entitled AiFoam. Benjamin Tee of the NUS Department of Materials Science and Engineering and the Institute for Health Innovation & Technology (iHealthtech) is the lead author and director of the research team.

The soft, sponge-like, artificially innervated foam aims to mimic the human sense of touch, and can therefore enable robots equipped with it to detect nearby objects without actually touching them. Benjamin Tee states:

“We want to show that it is possible to replicate the human sense of touch in a robot, which opens up a new paradigm in human-machine interaction for future applications. By having a foam with our special formulation, we can easily detect both the pressure of an object and the proximity of an individual.”

Goal: Give a robot a sense of touch using new technologies

On a daily basis, humans use their sense of touch to manipulate objects and thus adapt to known or even unknown environments. When machines that interact with humans have this ability, robotic movement can be smoother, safer and more predictable. Take cleaning robots, for example: if they can detect human presence at a distance and use the information to infer human intentions, they can react more quickly and avoid colliding with people, especially in crowded areas.

Some electronic “skins” have the ability to detect when they come into direct contact with an object, but AiFoam has a special feature: it detects the direction of movement of adjacent objects, and it is on this aspect that the researchers focused their study to design this intelligent foam.

Helping robots to better respond to their environment with AiFoam

AiFoam is a highly elastic polymer created by mixing a Teflon-like substance known as fluoropolymer with a surfactant. This results in a material that, when separated into pieces (by accident, for example), can easily fuse into a single piece if. The research team introduced microscopic metal particles into the foam that allows it to detect the presence of an object as a human finger might when touching an object.

As mentioned before, AiFoam is able to “feel” the presence of an object from a few centimeters away and can also detect human presence unlike other proximity sensors that use light and reflections to function.

To mimic the sensitive nerve endings in human skin, the researchers embedded thin cylindrical electrodes under the surface of the foam. They are able to detect the direction of the applied force, not just the “amount” of force. This would allow robots to better understand human intentions, or to know that a touching object is about to slip, so they can react more quickly and appropriately.

Benjamin Tee concludes by discussing the potential future applications of the foam his team has designed:

“AiFoam’s self-healing properties, as well as its sensitivity to a contact force, will allow robots to better judge human intent and build a future generation of robots that react quickly and more effectively to environmental changes.”

Translated from Un matériau intelligent sous forme de mousse permettrait aux robots d’être dotés du sens du toucher