Graphene micro-supercapacitors (MSCs) are an attractive energy storage technology for powering miniaturized portable electronics. Despite considerable advances in recent years, device fabrication typically requires conventional microfabrication techniques, limiting the translation to cost-effective and high-throughput production. To address this issue, we report here a self-aligned printing process utilizing capillary action of liquid inks in microfluidic channels to realize scalable, high-fidelity manufacturing of graphene MSCs. Microstructured ink receivers and capillary channels are imprinted on plastic substrates and filled by inkjet printing of functional materials into the receivers. The liquid inks move under capillary flow into the adjoining channels, allowing reliable patterning of electronic materials in complex structures with greatly relaxed printing tolerance. Leveraging this process with pristine graphene and ion gel inks, miniaturized all-solid-state graphene MSCs are demonstrated to concurrently achieve outstanding resolution (active footprint: <1 mm2, minimum feature size: 20 µm) and yield (44/44 devices), while maintaining a high specific capacitance (268 µF cm–2) and robust stability to extended cycling and bending, establishing an effective route to scale down device size while scaling up production throughput.
Bibliographical noteFunding Information:
This work was supported by the Multi-University Research Initiative (MURI) program (N00014-11-1-0690) sponsored by the Office of Naval Research. Support from the Air Force Research Laboratory under agreement number FA8650-15-2-5518 is also acknowledged. Parts of this work were performed at the Characterization Facility and the Nano-Fabrication Center of the University of Minnesota. W.J.H. was also supported by the MN Drive program at the University of Minnesota. E.B.S. was further supported by the Ryan Fellowship administered through the Northwestern University International Institute for Nanotechnology. The U.S. Government is authorized to reproduce and distribute reprints for Governmental purposes notwithstanding any copyright notation thereon. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the sponsors.
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
- flexible electronics
- ion gel
- printed electronics