Reconfigurable Liquid-Metal RF Circuits and Antennas Using Electrical Actuation

University Of Hawaii, Honolulu

Investigators

Abstract

The proposed research will investigate electrically controlled actuation of liquid metals, helping to create the foundation for the design of reconfigurable devices and circuits that use liquid metals. Reconfigurable electronics have the unique ability to change their operational parameters, allowing them to adapt to specific tasks or environments. The amorphous nature of liquid metal allows for the creation of dynamic conductors whose shape and position can be altered to adapt to changing environments or operating parameters. Imagine, for example, a mobile electronic device that can reconfigure its communication system to provide the highest efficiency, and thus the longest battery life, in a variety of environments. This research has the potential to impact the electronics and telecommunication industries, and can enable more effective and efficient use of the wireless frequency spectrum. In addition, the research into the actuation methods has applications to fields outside of reconfigurable electronics, including microfluidics and lab- on-chip systems. This project will also support the inclusion of underrepresented Native Hawaiian students, will involve undergraduate students in the proposed research, and will support outreach to K-12 students. We will investigate low-voltage electrically controlled actuation methods for the actuation of liquid metals, and tailor these methods to applications in reconfigurable radio-frequency (RF) circuits. The actuation methods that will be focused on include a novel hybrid form of electrocapillary and electrochemical actuation, electrical capillary actuation coupled with quantized shapes of liquid metal, and continuous electrowetting. Reconfigurable circuits using each type of actuation method will be demonstrated: liquid-metal antennas that can shapeshift to change their operating characteristics, and microwave-frequency switches that have the potential for low insertion loss, high isolation, and high reliability. The proposed research will also address an important issue in liquid-metal devices: loss at microwave frequencies due to the use of aqueous electrolytes. Device architectures will be developed that are agnostic to this effect, take advantage of the loss, or minimize the loss by removing or displacing the electrolyte. The adaptation of each proposed liquid-metal actuation method to the unique constraints and requirements of reconfigurable circuits is novel. The actuation methods will be showcased by creating new types of reconfigurable circuits operating at microwave frequencies. The resulting devices will have performance characteristics that are unique or that exceed the current state-of-the-art in reconfigurable electronics. Thus, this research will advance the field of liquid-metal circuits, and create new technologies for realizing reconfigurable RF circuits. New knowledge of liquid-metal actuation will be generated. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.