MIT’s Hair Brushing Robot is Set to Redefine Hair Grooming

This hair brushing robot will simplify untangling for people with limited mobility

Recently scientists from MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL) and the Soft Math Lab at Harvard University, together developed a hair-brushing robot. The robotic arm has a sensorized soft brush, camera with force feedback, and closed-loop control, that can identify different hair types and groom accordingly.

A paper was published on this soft robot by Josie Hughes, Thomas Bolton Plumb-Reyes, L. Mahadevan, and Daniela Rus. The robotic hairbrush, called 'RoboWig' is intended in reducing the pain involved in untangling hair and to assist the elderly, young, and people with limited mobility in the process of grooming their hair. The paper reveals that this soft robot leverages a model of entangled soft fiber bundles and mathematical algorithms that can identify tangled hair as entwined double helices. The sensorized soft bristle end effector can efficiently measure the forces during brushing and also creates fore-feedbacks that ensure that the user can control the device and feel what it is up to.

The team has performed many experiments to validate the innovation. According to the paper, "First, we show repeated brushing of a single wig with the brushing height fixed. We see the expected rise in force as the hair fibers start to jam, after which the force applied to the brush overcomes this jamming force and brushes free. The brush force is the highest for the first brush, however, reduces with brushing iterations as with each brush a number of entanglements are removed."

The camera on the robot arm clicks the picture of the hair, analyses it by converting it to Grayscale images, by using horizontal and vertical (x/y) gradient ratio, and finally performs computations to understand the texture, straight or curly. The paper says that this project is proposed to use sigmoid function and computer vision to select the brushing heights for different hairs and identify the curliness of the hair respectively. Also, it says that there is an increased need for conducting human-based experiments to understand the 'pain' factor properly and get subjective feedback. This nascent innovation is pathbreaking since untangling hair is a complex process and robots should not cause pain, but should also be able to put enough pressure necessary to untangle it. While speaking to MIT News, Josie Hughes told that "In addition to hair brushing, the insights provided by our approach could be applied to brushing of fibers for textiles, or animal fibers."