University of Hawaii

Electrical Engineering

Reconfigurable Liquid-Metal Circuits and Antennas: Magnetic and Pressure-Based Actuation for Improved Performance at Microwave Frequencies

Date: 2018-08-06           Add to Google Calendar
Time: 6:00pm
Location: Holmes Hall 389
Speaker: Anthony W. Combs, EE MS Candidate


The proliferation of wireless devices and the need for new, adaptive technologies which operate at radio- and microwave frequencies have given rise to reconfigurable RF devices can modify one or more parameters, often independently, which may be desired in applications where an operating requirement is unknown or must be satisfied over multiple domains. A less conventional approach being explored in developing reconfigurable technologies is by using non-toxic gallium-based liquid-metal alloys. Liquid metals, which are liquid at room temperature, have self-healing properties, are amorphous, have relatively high conductivities, and have proven to be effective in a multitude of RF devices and applications. This work demonstrates two new methods of actuating (i.e. manipulating) liquid metal and a device application for each. The first method, ferrofluid actuation, utilizes the physical deformation of ferrofluid in response to a magnetic field to displace, or transport, liquid metal from one location to another. This technique is demonstrated and shown in a functional RF switch. The second method described in this work, pressure-point actuation, enables small volumes of liquid metal, referred to as nodes, to be split apart or merged together to incrementally alter the length or shape of a liquid-metal conductor. This technique is demonstrated and shown in a frequency-reconfigurable dipole with liquid-metal nodes.