Tugce Akyazi

Electrochemical characterization of ionogel actuators

Ionogels (IOs) have been characterized by Electrochemical Impedance Spectroscopy (EIS) using gold interdigitated electrodes (Au-IDEs). Poly(N-isopropylacrylamide) (pNIPAAm) was photopolymerized in the presence of two ionic liquids (ILs), 1-ethyl-3-methylimidazolium ethyl sulfate [C2mIm][EtSO2] (1) or trihexyltetradecyl-phosphonium dicyanamide [P6,6,6,14][DCA] (2). The properties of the ILs are directly transferred to the IO and differences in Charge Transfer Resistance (Rct) were measured between the swelling and drying states. It was observed that IO-2 traps water molecules in a stronger way than IO-1, therefore its swollen state is more stable. Additionally, the resulting porosity was analyzed and related with their ability to accommodate water. These studies ensure a better understanding of the actuator behavior of the IOs.

CHAPTER 9:Applications of Ionic Liquid Materials in Microfluidic Devices

“Lab-on-a-chip” (LOC) and microfluidics enable the manipulation of fluids at small length scales (from micrometers to millimeters). These systems often have well-defined fabrication processes and are capable of integrating multiple functional elements, to provide complete sample-in/answer-out systems. Nevertheless, the development of fully integrated microfluidic devices still faces some considerable obstacles, including fluidic control, miniaturisation and high costs. Due to their unique properties, ionic liquids have arisen as smart solutions to circumvent some of the hurdles facing current LOC technologies. They can directly benefit microfluidic devices by aiding miniaturised fabrication and passive microfluidic elements for fluid control, sensing and sample storage. Improved chemical reactions and separation, in addition to power generation, temperature control, and electrowetting show potential for reducing manufacturing costs and widening market possibilities. In this chapter we will review and discuss the fundamental applications of ionic liquids within microfluidic systems.