Sub-Millisecond Post Exposure Bake of Chemically Amplified Photoresists by CO 2 Laser Spike Annealing

A microfluidic device is fabricated to characterize the streaming electrokinetic potential on the surface of charged electrospun nanofibers. The electrodes are made of evaporating with Ti and Au on an insulator, Pyrex® wafer, and are covered by a PDMS microchannel to form a microfluidic channel. The cationic or anionic charges of the electrospun charged nanofibers on the electrodes are interacting with the counter ions in the buffer solution. A voltage changes are traced by a source meter during the flow of buffer solution into the channel and the electrokinetic potential of the charged nanofibers is calculated, which is brought about when pressure-driven flow in a microchannel forms double layer ions. Figure 1: Schematic diagram for positioning electrospun fibers across a microchannel (a) and along the length of a microchannel (b). Arrows indicate the direction of buffer solution flow within the microchannel. Summary of Research: It has been commonly known that nanofiber surfaces are chemically and biologically modified to make functionality on them, in order to apply for bio-analysis; such as sample purification, and detection as acting on nano-guiding lines within the microfluidic channel [1]. The nanofibers can be electrospun, arranging them across the microchannels, or along the microchannels in order to create distinct immobilization strings within the channels, or to function as guiding structures for cell movement (see Figure 1). The preliminary studies of nanofiber applicability are provided to conduct the functional investigations as biofunctional guiding structures in microchannels, as biological separators in sample clean up and analyte concentration steps, and also for enhanced immobilization of biorecognition elements. The nanofiber density in the microchannels before and after fluid flow is quantified in order to determine the durability of nanofibers within the microchannels. The nanoscale particles having carboxyl, sulfon, or amino groups have been incorporated into electrospun fibers to create the functional and bioactive sites on the fiber surface. These particles intrinsically have their own charge potentials according to the buffer solution. The extremely large specific surface area of nanofibers maximizes the availability of functional groups bound on the surface of the electrospun fibers. The particles are mixed into the mother polymer spinning dopes such as poly vinyl alcohol (PVA) or poly(lactic acid) (PLA), which are then jet to form the nano-scale fibers Figure 2: Positively charged nanofibers will be used as separators within a microchannel (a) and negatively charged ones as guiding structures (b).