Development of PDMS-based micromachining process for microfluidic reconfigurable antennas /

Seyedpour Esmaeilzad, SeyedehNasim
The objective of this thesis is to develop fabrication methods to implement microfluidic-based reconfigurable antennas. As the initial structure, a microfluidic based reconfigurable antenna is developed for transmitarrays, which consists of a multi-layered structure incorporating a microfluidic channel to confine liquid metal. The microfluidic channels are fabricated using soft lithography techniques where the channel material is PDMS. PDMS-to-glass and PDMS-to-PDMS bonding processes are optimized to achieve a reservoir for the fluidic material. In particular, a split-ring resonator and a complementary split ring for transmitarray applications are manufactured using the optimized process. Instead of using direct metallization approach, which is inadequate because of the low surface strength of PDMS, a novel method is proposed for the bonding of two different surfaces. A thin layer of silicon dioxide (50 nm) is deposited on the metal layer before the oxygen plasma treatment. The oxygen plasma treatment is done for duration of 20 seconds at an RF power of 20 W. Bonding strength measurements are also performed in the frame of this thesis. It is noted that the bonding quality can be enhanced with the use of silicon dioxide intermediate layer. The other device that has been designed and manufactured is a frequency tunable patch antenna, which is formed by reconfiguring its dimension employing two rectangular patches that are joined to each other with a liquid metal channel. The microfluidic channel is created by applying the bonding method between PDMS and metallized glass layers. The antenna has two different operation modes: (i)The channel is empty and the antenna resonates at 10.68 GHz and (ii) the condition in which the channel is full of liquid metal and the antenna resonates at 9.62 GHz. In conclusion, microfluidic transmitarray and microfluidic reconfigurable antenna are fabricated using liquid metal channel embedded in the PDMS layer.
Citation Formats
S. Seyedpour Esmaeilzad, “Development of PDMS-based micromachining process for microfluidic reconfigurable antennas /,” M.S. - Master of Science, Middle East Technical University, 2015.