While your body hair can help keep you warm, that’s not its sole purpose for modern humans. In fact, most of us likely aren’t gaining any meaningful amount of warmth from our body hair—at least over most of our bodies. Instead, our body hair helps to enhance our sense of touch. It can help us detect weak air currents, or light touches. As researchers from the Auckland Bioengineering Institute at the University of Auckland in New Zealand have demonstrated, we can augment our body hair to gain additional senses.
The most interesting aspect of this M-Hair research is how simple it is. In a world where we frequently try to solve problems through complex technological means, this work is downright Luddite. All a user has to do is spread a simple paste across the body hair on some part of their body, such as their forearm. That paste contains fine ferrous particles that are responsive to magnetic fields. Whenever a strong enough magnetic field is present, the body hair will be attracted to that field and the user will be able to easily detect that attraction.
To test that new sense, they coated users’ forearm hair with the magnetically-responsive paste. They then positioned their arms under a modified laser engraver. The laser was removed and replaced with a rare earth magnet. But sending precise control commands to the machine, they were able to draw consistent patterns in two dimensions. The test subjects weren’t able to see the machine’s movement, and were challenged to identify the shapes being drawn.
While they weren’t able to accurately or consistently identify any complex shapes, they could recognize simple shapes and motions. Most of the test participants described the sensation as “windy,” and found it to be gentle and subtle. It’s unlikely that this augmented sense would be able to provide any precision, but it could be a practical way to provide simple haptic feedback without requiring any of the electronic components found in most wearable devices.