The wristband features built-in organic photovoltaics that collect solar energy to power a fitness tracker.
Organic photovoltaics, called OPV’s, are produced with roll-to-roll or screen-printing techniques that deposit different non-toxic inks onto a flat substrate like clear polymer films. To improve the energy harvesting performance, also in low light conditions, researchers from Advent-Energy developed new ink formulations.
To integrate the OPV’s alongside an NFC antenna that allows for wireless top-up charging, all components were overmolded by researchers from VTT with soft TPE, a material that is commonly used for sport watch straps.
To study and monitor power generation in everyday life situations, developers from Polar built a connected strap that transmits real-time solar harvesting data to a smartphone app.
To maximize energy harvesting potential, we explored the idea of increasing the usable OPV surface. The challenge was to find patterns and perforations that keep the solar-active cells on the semiflexible substrate bendable enough during sport activities and allow for ventilation.
Together with Hadrien Fouin, Anna Röder, Amelie Graf, Agatha Sowinski, Nina Eder, Valerie Feiertag
We are grateful for the opportunity to collaborate in this interdisciplinary project. We very much appreciate the contributions of everyone who was involved and would like to mention:
Juhani Kemppainen
Mari Ylikunnari
Thomas Herndl
Mladen Pesic
Christos Chochos
Katie Beverley
Polar
VTT
Infineon
Infineon
Advent Energy
PDR
Finland
Finland
Austria
Austria
Greece
UK
This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 761112
