Stretchable supercapacitors have received increasing attention due to their broad applications in developing self‐powered stretchable electronics for wearable electronics, epidermal and implantable electronics, and biomedical devices that are capable of sustaining large deformations and conforming to complicated surfaces. In this work, a new type of highly stretchable and reliable supercapacitor is developed based on crumpled vertically aligned carbon nanotube (CNT) forests transferred onto an elastomer substrate with the assistance of a thermal annealing process in atmosphere environment. The crumpled CNT‐forest electrodes demonstrated good electrochemical performance and stability under either uniaxial (300%) or biaxial strains (300% × 300%) for thousands of stretching–relaxing cycles. The resulting supercapacitors can sustain a stretchability of 800% and possess a specific capacitance of 5 mF cm−2at the scan rate of 50 mV s−1. Furthermore, the crumpled CNT‐forest electrodes can be easily decorated with impregnated metal oxide nanoparticles to improve the specific capacitance and energy density of the supercapacitors. The approach developed in this work offers an alternative strategy for developing novel stretchable energy devices with vertically aligned nanotubes or nanowires for advanced applications in stretchable, flexible, and wearable electronic systems.
Multilayer dielectric elastomer actuators have a wide range of potential applications, but their development and commercial implementation have been hindered by existing manufacturing processes. Existing processes are low‐throughput, limited in area, and/or can only process a narrow range of elastomers. This study presents a novel fabrication paradigm that overcomes these challenges: instead of sequentially patterning electrodes directly onto successive elastomer layers, electrode stamps are patterned onto a carrier film in an independent batch‐spray process and the electrodes are then stamp‐transferred onto each elastomer layer. By modularizing the production and assembly of electrodes, a laboratory‐scale implementation of the process achieves a throughput of 15 layers h−1, a maximum electrode size of 300×300 mm, and tuning‐free compatibility with a wide range of elastomers. The batch‐spraying paradigm also provides the unique capability to evaluate and modify electrodes before they are assembled into a multilayer; a method of mechanically treating the electrodes is employed to increase the breakdown strength of Elastosil P7670 devices from 15.7 to 33.5 V µm−1. The electrodes are conductive up to a strain of more than 200% and add negligible stiffness to the multilayer structure. The capabilities of this process to produce useful devices are demonstrated with a large‐area loudspeaker and an actuator with 60 active layers.
more » « less- NSF-PAR ID:
- 10444119
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 32
- Issue:
- 43
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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