The concept involves using solar cells placed under the skin to be continuously recharge implanted electronic medical devices. Some success has been achieved at a Swiss based research institutes: Bern University Hospital and the University of Bern. The lead scientist behind the project is Professor Lukas Bereuter.
The analysis by the scientists shows that a 3.6 square centimeter solar cell is sufficient to generate enough power, during winter and summer, to power a standard pacemaker. As well as pacemakers, the researchers have also been looking at devices designed to trigger deep brain stimulation. Deep brain stimulation is a neurosurgical procedure involving the implantation of a medical device called a neurostimulator, designed to send electrical impulses to specific targets in the brain (brain nuclei) to treat of movement disorders.
The main aim of solar technology, Tech Briefs reports, with this application, is to protect patients. Here the idea of wearing power-generating solar cells under the skin will avoid the necessity of patients having to undergo invasive procedures to change batteries. The majority of medical implants are battery-powered. The size of the device, and thus its functionality and life-expectancy, is a product of the battery volume. When battery power runs out patients need to undergo implant replacement procedures.
The use of solar cells overcomes the need for replaceable batteries, with the cells converting the light from the sun into usable energy. The process requires sunlight to penetrate the skin surface. In trials, Professor Bereuter has investigated the use of solar-powered rechargeable energy generators. The cells tested were 3.6 square centimeters in size. In his trial, 10 devices were covered with optical filters to test how different properties of the skin influence the extent that sun penetrates the skin. Here 32 volunteers in Switzerland wore the devices for for one week during three seasons: summer, autumn, and winter.
It was found that irrespective of the season, the micro-sized cells could generate between the 5 to 10 microwatts of power, which is sufficient to charge a cardiac pacemaker. From this success, further trials will be conducted.
The research has been published in the journal Annals of Biomedical Engineering. The title of the paper is “Energy harvesting by subcutaneous solar cells: A long-term study on achievable energy output.”
