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Abstract Liquid metals, such as Gallium‐based alloys, have unique mechanical and electrical properties because they behave like liquid at room temperature. These properties make liquid metals favorable for soft electronics and stretchable conductors. In addition, these metals spontaneously form a thin oxide layer on their surface. Applications made possible by this delicate oxide skin include shape reconfigurable electronics, 3D‐printed structures, and unconventional actuators. This paper introduces a new approach where liquid metal oxide serves as an electrochemical energy source. By mechanically rupturing their surface oxide, liquid metals form a galvanic cell and convert their chemical energy to electrical energy. When dispersing liquid metals into an ionically‐conductive liquid to form emulsions, this composite material can provide ∼500 mV of open‐circuit voltage and up to ∼4 μWof power. Protected by the naturally occurring oxide skin, the passivating oxide layer of the liquid metal shields it from self‐discharge over time. The device is also stable in harsh environments, such as high temperature or aquatic conditions. Future applications of this device are demonstrated by designing a strain‐activated stretchable battery and a pressure‐sensitive self‐powered keypad. These findings may unlock new pathways to design stretchable batteries and harness their inherent energy for self‐powered robust devices.
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Annealing for controlled galinstan oxide thin-film morphological and electromechanical properties
Gallium-based liquid metals are unique in their deformably, conductive nature and the oxide that grows natively on their surface. The oxide of galinstan, gallium–indium–tin, is composed of Ga/In/Sn oxides known for their semiconducting properties. The native galinstan oxide, however, is amorphous and improving electrical properties is understudied. In this work, annealing, a method for improving conductivity and hardness in metals and ceramics, is studied to control galinstan oxide crystallinity, modulus, and resistivity. It was found that while annealing increases crystallinity and grain size, local composition and thickness must also be considered when analyzing galinstan oxide electrical and mechanical properties.
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- Award ID(s):
- 2000053
- PAR ID:
- 10382437
- Date Published:
- Journal Name:
- MRS Communications
- ISSN:
- 2159-6867
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1557/s43579-022-00295-1
