title: Energy Harvesting by Subcutaneous Solar Cells: A Long-Term Study on Achievable Energy Output.
abstract: Active electronic implants are powered by primary batteries, which induces the necessity of implant replacement after battery depletion. This causes repeated interventions in a patients' life, which bears the risk of complications and is costly. By using energy harvesting devices to power the implant, device replacements may be avoided and the device size may be reduced dramatically. Recently, several groups presented prototypes of implants powered by subcutaneous solar cells. However, data about the expected real-life power output of subcutaneously implanted solar cells was lacking so far. In this study, we report the first real-life validation data of energy harvesting by subcutaneous solar cells. Portable light measurement devices that feature solar cells (cell area = 3.6 cm2) and continuously measure a subcutaneous solar cell's output power were built. The measurement devices were worn by volunteers in their daily routine in summer, autumn and winter. In addition to the measured output power, influences such as season, weather and human activity were analyzed. The obtained mean power over the whole study period was 67 µW (=19 µW cm-2), which is sufficient to power e.g. a cardiac pacemaker.
authors.affiliation: Department of Cardiology, Bern University Hospital, 3010, Bern, Switzerland.|ARTORG Center for Biomedical Engineering, University of Bern, 3008, Bern, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Bereuter
authors.affiliation: ARTORG Center for Biomedical Engineering, University of Bern, 3008, Bern, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Williner
authors.affiliation: Laboratory for Thin Films and Photovoltaics, Swiss Federal Laboratories for Materials Science and Technology Empa, 8600, Duebendorf, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Pianezzi
authors.affiliation: Laboratory for Thin Films and Photovoltaics, Swiss Federal Laboratories for Materials Science and Technology Empa, 8600, Duebendorf, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Bissig
authors.affiliation: Laboratory for Thin Films and Photovoltaics, Swiss Federal Laboratories for Materials Science and Technology Empa, 8600, Duebendorf, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Buecheler
authors.affiliation: Haute Ecole Arc Ingénierie - University of Applied Sciences and Arts Western Switzerland (HES-SO), 2300, La Chaux-de-Fonds, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Burger
authors.affiliation: Department of Cardiology, Solothurner Spitäler AG, 4500, Solothurn, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Vogel
authors.affiliation: Department of Cardiology, Bern University Hospital, 3010, Bern, Switzerland.|ARTORG Center for Biomedical Engineering, University of Bern, 3008, Bern, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Zurbuchen
authors.affiliation: Department of Cardiology, Bern University Hospital, 3010, Bern, Switzerland. andreas.haeberlin@insel.ch.|ARTORG Center for Biomedical Engineering, University of Bern, 3008, Bern, Switzerland. andreas.haeberlin@insel.ch.|Department of Cardiology, Bern University Hospital and University of Bern, c/o ARTORG Center for Biomedical Engineering Research, Murtenstrasse 50, 3008, Bern, Switzerland. andreas.haeberlin@insel.ch.
authors.forename: A
authors.initials: A
authors.lastname: Haeberlin
mesh_terms: D004581:Electronics / Q000295:instrumentation*; D006801:Humans; D020007:Implants, Experimental; D012621:Seasons; D012867:Skin; D012993:Solar Energy
keywords: Feasibility; Light exposure; Light transmittance; Medical implants; Pacemaker; Photovoltaic; Power; Skin