Liquid‐metal frequency‐reconfigurable slot antenna using air‐bubble actuation

Abstract

Liquid metal actuated by pressure-driven air bubbles is guided within channels to dynamically reconfigure the length of the radiating aperture and feed line of a slot antenna. The gallium-based liquid metal is held in position by air bubbles, and liquid-metal motion is induced when a pressure differential is created. In contrast to conventional hydraulic or pneumatic actuation of gallium-based liquid metal, the pressure actuation described here is reversible and repeatable, as the liquid metal is enveloped by a thin layer of NaOH solution, which acts as a slip layer and reduces any metal oxidation. The slot antenna achieves a 26% tunable bandwidth with a contiguous range from 1.42 to 1.84 GHz for which the S 11 is <−10 dB. The peak gain ranges from 4.8 dBi in its lowest-frequency state to 4.1 dBi in its highest-frequency state.

Unconventional locomotion of liquid metal droplets driven by magnetic fields

“…Interestingly, unlike a solid metal sphere, there is a slip layer existed between the solid-liquid interface for liquid metal placed in a solution. [39][40][41] Such a slip layer can act as a lubricant to prevent the rolling of the droplet and consequently, the horizontal force Fe will induce the actuation of EGaIn droplet towards the travelling direction of the magnet ( Figure 1C). [39][40][41] To examine the hypothesis and investigating the actuating behavior, we established an actuating platform consisting of a circular PMMA channel with a semi-circular cross section groove, and permanent magnets driven by a DC motor travelling underneath the PMMA channel, as shown in Figure 1D.…”

Liquid‐metal‐fluidically polarization reconfigurable microstrip patch antenna

“…Finally, there is a frequency or polarization reconfigurable antenna using fluidic tuning components. The variable method with fluidic tuning components physically changes the structure by using a material with the characteristics of both liquid and metal . A frequency reconfigurable antenna is proposed, which reconfigures the length of the feed line and the length of the radiating aperture of the slot antenna by adjusting the liquid metal actuated by pressure‐driven air bubbles .…”

“…The variable method with fluidic tuning components physically changes the structure by using a material with the characteristics of both liquid and metal . A frequency reconfigurable antenna is proposed, which reconfigures the length of the feed line and the length of the radiating aperture of the slot antenna by adjusting the liquid metal actuated by pressure‐driven air bubbles . A polarization reconfigurable antenna is proposed, which can be reconfigured using liquid metal for five discrete states with varying polarizations and null directions .…”

“…[18][19][20][21][22][23][24] A frequency reconfigurable antenna is proposed, which reconfigures the length of the feed line and the length of the radiating aperture of the slot antenna by adjusting the liquid metal actuated by pressure-driven air bubbles. 24 A polarization reconfigurable antenna is proposed, which can be reconfigured using liquid metal for five discrete states with varying polarizations and null directions. 22 A glass dielectric resonator with a liquid-metal polarizer is introduced for a polarization reconfigurable antenna.…”

A flexible liquid-metal alloy bandpass filter

“…Recently, some microwave components by adopting the properties of liquid metal have been designed, such as antennas, filters, and so forth. For example, using the fluidity of the liquid metal, a frequency‐reconfigurable slot antenna and a wideband frequency‐tunable monopole antenna are presented. By dynamically moving the liquid metal to reshape the resonator, a frequency‐agile second order filter is designed in reference, where fluid metal layer is placed on a Rogers 5880 substrate with a thickness of 1.575 mm.…”