Encapsulated, High-Performance, Stretchable Array of Stacked Planar Micro-Supercapacitors as Waterproof Wearable Energy Storage Devices.
We report the fabrication of an encapsulated, high-performance, stretchable array of stacked planar micro-supercapacitors (MSCs) as a wearable energy storage device for waterproof applications. A pair of planar all-solid-state MSCs with spray-coated multiwalled carbon nanotube electrodes and a drop-cast UV-patternable ion-gel electrolyte was fabricated on a polyethylene terephthalate film using serial connection to increase the operation voltage of the MSC. Additionally, multiple MSCs could be vertically stacked with parallel connections to increase both the total capacitance and the areal capacitance owing to the use of a solid-state patterned electrolyte. The overall device of five parallel-connected stacked MSCs, a microlight-emitting diode (μ-LED), and a switch was encapsulated in thin Ecoflex film so that the capacitance remained at 82% of its initial value even after 4 d in water; the μ-LED was lit without noticeable decrease in brightness under deformation including bending and stretching. Furthermore, an Ecoflex encapsulated oximeter wound around a finger was operated using the stored energy of the MSC array attached to the hand (even in water) to give information on arterial pulse rate and oxygen saturation in the blood. This study suggests potential applications of our encapsulated MSC array in wearable energy storage devices especially in water.
Department of Chemical and Biological Engineering, Korea University , 5-1 Anam-dong, Seoul 13l-701, Korea.
Hyoungjun
H
Kim
Department of Chemical and Biological Engineering, Korea University , 5-1 Anam-dong, Seoul 13l-701, Korea.
Jangyeol
J
Yoon
KU-KIST Graduate School of Converging Science and Technology , 5-1 Anam-dong, Seoul 13l-701, Korea.
Geumbee
G
Lee
Department of Bio-convergence Engineering, Korea University , Seoul 136-703, Korea.
Seung-Ho
SH
Paik
Department of Civil, Environmental and Architectural Engineering, Korea University , Seoul 136-701, Korea.
Gukgwon
G
Choi
Department of Chemical and Biological Engineering, Korea University , 5-1 Anam-dong, Seoul 13l-701, Korea.
Daeil
D
Kim
Department of Bio-convergence Engineering, Korea University , Seoul 136-703, Korea.
Beop-Min
BM
Kim
Department of Civil, Environmental and Architectural Engineering, Korea University , Seoul 136-701, Korea.
Goangseup
G
Zi
Department of Chemical and Biological Engineering, Korea University , 5-1 Anam-dong, Seoul 13l-701, Korea.|KU-KIST Graduate School of Converging Science and Technology , 5-1 Anam-dong, Seoul 13l-701, Korea.
Jeong Sook
JS
Ha
encapsulation; liquid metal; micro-supercapacitor; oximeter; stretchable; waterproof