Getting Yourself Out of a Tangle

When learning about a robot that was designed to brush hair, people will usually have one of two reactions — either excitement that the robot barber from The Jetsons has nearly become a reality, or astonishment that someone would build a device for such a seemingly trivial purpose.

Thanks to a collaboration between MIT CSAIL and Harvard University, that hair brushing robot has become a reality. And it may be more useful than you think; in some healthcare settings, nurses spend up to 40% of their time on direct patient care tasks such as this.

Seemingly simple tasks can be deceptively complex when getting into the details, and combing hair is no exception. Pulling too hard is painful, but not applying enough force will get the brush stuck. And of course there are different types of hair to deal with — straight hair and curly hair need a different approach.

To account for these complexities, the team outfitted a robot arm with a sensor-laden soft hair brush and a camera. The sensors in the brush provide feedback about the amount of force being applied so that the robot knows if it is getting caught in a snag or otherwise being too forceful. The camera is used to assess the curliness of the hair to form an appropriate brushing strategy that balances delicacy and time efficiency.

Hair strands were represented as double helices and fed into mathematical models that inform the robot’s control systems. This allowed the robot to “learn” techniques that people already know from experience, like beginning at the ends of the hair strands, then working upwards.

Initial testing of the robot has been on mannequin heads wearing wigs, which shows the process working. And while no mannequins have complained about any discomfort, the team is still planning future experiments with human participants to gain insight into the subjective measures of discomfort that may be present.

While brushing hair may seem like a small task to most of us, this automated solution has real potential to give additional independence to the elderly and mobility impaired, while simultaneously taking some of the burden off of caregivers and medical professionals.