Tracking your daily physical activity could be as easy as putting on a pair of socks. Self-charging socks that are powered by your steps can monitor walking patterns and could also power wearable devices.
The socks are coated in a material that conducts electricity. Contact between them and either the floor or a pair of shoes creates a small electrical current from static electricity.
The energy generated can then either be stored or used to supply other wearable devices, says Minglu Zhu at the National University of Singapore, one of the creators of the socks.
Advertisement
This process of contact electrification is called the triboelectric effect and is the reason people sometimes get electric shocks when touching a metal object.
Embedded in the socks are chips that sense pressure. These can monitor movement, training intensity and even medical conditions that affect people鈥檚 walking, such as Parkinson鈥檚 disease.
鈥淧arkinson鈥檚 disease is difficult to evaluate in a routine clinical examination,鈥� says Zhu. By continuously monitoring walking patterns for abnormalities, such as sudden freezing, the socks could aid diagnosis.
The socks still have wires, but because they are much thinner than the yarn the socks are made from, they are easily hidden.
鈥淲ashing will not affect the sensing capability of the sock,鈥� says Zhu. But it does thin the conductive layer, reducing the amount of energy the sock generates.
For the moment, the socks don鈥檛 generate enough energy to continuously power wearable devices other than the on-board chips. But the team plans to add this capacity in the future.
ACS Nano
