Tunable frequency antenna integrated with microfluidic channel

A tunable frequency antenna integrated with microfluidic channel is proposed to mimic change of shorting pin location by the movement of the conducting liquid through the channels. The antenna is fabricated on FR4 substrate and Polydimethylsiloxane (PDMS) layers are used to form and protect channels. It is shown that by moving the conductive liquid, antenna resonant frequency can be tuned in the range of 4.8 to 5.4 GHz. For this purpose, Galinstan, high quality conductive liquid which is an alloy of gallium, indium, and tin with electrical conductivity of 3.46×10⁶ S/M is preferred. A micropump is used to pull and push the liquid inside the channel and liquid Teflon is used to refresh the galinstan tracks. Measurement results of the fabricated antenna agree well with the simulations.