Solar panels under the skin set to power medical devices

A 3.6 square centimetre solar cell can continuously recharge implanted electronic medical devices, study finds

Swiss researchers have found that a 3.6 square centimetre solar cell is all that is needed to continuously recharge implanted electronic medical devices, such as pacemakers and deep brain stimulators.

Lead author Lukas Bereuter of Bern University Hospital and the University of Bern said wearing power-generating solar cells under the skin will one day save patients the discomfort of having to continuously undergo procedures to change the batteries of such life-saving devices.

Bereuter and his colleagues developed specially designed solar measurement devices that can measure the output power being generated by cells. For the test, each of the 10 devices were covered by optical filters to simulate how properties of the skin would influence how well the sun penetrates the skin. These were worn on the arm of 32 volunteers in Switzerland for one week during summer, autumn and winter.

No matter what season, the tiny cells were always found to generate much more than the 5 to 10 microwatts of power that a standard pacemaker uses. The participant with the lowest power output still obtained 12 microwatts on average.

Bereuter said: "The overall mean power obtained is enough to completely power, for example, a pacemaker or at least extend the lifespan of any other active implant. By using energy-harvesting devices such as solar cells to power an implant, device replacements may be avoided and the device size may be reduced dramatically."

He believes that the results of this study can be scaled up and applied to any other mobile, solar powered application on humans. Aspects such as the catchment area of a solar cell, its efficiency and the thickness of a patient's skin must be considered.

The findings of the study, the first to provide real-life data about the potential of using solar cells to power medical devices, can be found in Annals of Biomedical Engineering.