A Flexible Foldable Tubular μDMFC for Powering Wearable Devices

This paper demonstrates a flexible tubular passive micro direct methanol fuel cell (μDMFC) featured by flexible electrodes and foldable whole structure for powering wrist bands the first time. A novel foldable structure, its fabrication, and assembly method proposed are usable for the flexible tubular μDMFCs and even other multi-layer flexible microfluidic devices. The test results show that the prototype achieves a power density of 15.3 mWcm -2 and a maximum output of 38 mW at room temperature. After 100 bending cycles (180 bending angle), the performance of the μDMFC decreases about 7.8%. Furthermore, the assembled μDMFC with a dc-dc converter is integrated into a wrist band to power an LED and dc motor (25 mW) for about 21 h with consumption of 1-mL methanol solution (50 wt%). It is believed that this μDMFC is applicable to serve as the power unit for wrist bands (typically 1~20 mW) or even other wearable devices. [2016-0142].