In this paper, we demonstrate recent progress in graphene-based photonic waveguide devices such as polymer
waveguide polarizer, thermo-optic mode extinction modulator and plasmonic photodetector for graphene-based
photonic integrated circuits.
The blood is one of the best indicators of health because blood circulates all body tissues and collects information. The COC(Cyclo Olefin Copolymer) has better various properties than PMMA(Polymethy Mechacrylate) and PC(Polycarbonate) that are widely used in biotechnology field. This paper presents a new method of plasma separation on the COC in terms of surface modification for the development of a disposable protein chip. The blood plasma separation device was composed of a whole blood inlet, microchannel with filtration region of micropillars, micropump with microheater, and a blood cell outlet. Micropump with microheater was designed by ANSYS and flow model in the microchannel was designed by CFD-ACE+ simulators. We successfully fabricated a polymer based microfluidic device for blood plasma separation by MEMS(Micro Electro Mechanical System) technology. By using this device, cell-free plasma was successfully obtained through the filtration from a drop of whole blood without external force of a syringe pump.
In this paper, we describe a novel multiplexed surface plasmon resonance (SPR) sensor which is made of cyclic olefin copolymers (COCs, TOPASTM). This material has excellent chemical resistance, low water uptake (< 0.01%), and high refractive index (nHe-Ne=1.53) suitable to use as an optical coupler (prism) as well as a sensor substrate. We fabricated a standard slide glass sized, prism integrated, and injection molded COC-SPR sensor which are being applied toward the multiplexed detection of DNA single nucleotide polymorphism (SNP). To evaluate the sensitivity of COC-SPR sensor, we first patterned MgF2 on gold-coated COC-SPR sensor and observed the shift of minimum reflectivity (SPR dip) in pixel address. As incident light source we used an expanded, collimated, rectangular shaped He-Ne laser, with a diffuser for beam homogenization. With expanded laser beam we varied incident angle so that the angular shift is expressed as the darkest pixel shift on CCD. For optimized SPR characteristics and sensor configuration, analytical calculations (Fresnel equation) were performed, and the best SPR conditions were found to be dAu~48 nm at wavelength λ=633 nm with respected resonance angle at θSPR =44.2° for COC-SPR sensor.
We present a novel technology for a cyclo-olefin-copolymer (COC) plastic microfluidic platform for heat control with fully semiconductor process-compatible photolithographic 5 μm-wide metal patterns, for heaters, electrodes, and temperature sensors and a thin membrane structure. Through tests of compatibility of some thermoplastic materials with chemical solutions and temperature tolerance to the semiconductor processes (thin film depositions, photolithography, and etchings), we selected COC as a semiconductor process-compatible plastic material for biomedical applications. For photolithography processes, we manufactured the 5’ COC wafer with flat surface with c.a. 3 nm surface roughness, employing a novel flame-torched injection-molding method. Furthermore, the part of heating blocks on COC wafers is controlled thickness to the 100 μm, to enhance the heat-ramping speeds through reduction of the thermal mass. In order to fabricate the Au thin film micro-patterns for temperature sensors, heaters, and electrodes, Au film (100 nm) was deposited by e-beam evaporator and patterned by using standard photolithography, and wet-etched. The micro-patterned Au temperature sensors, heaters, and electrodes was demonstrated. For insulating layers, Al2O3 film was deposited by an ALD system, patterned by using the standard photolithography, and wet-etched. Using the COC microfluidic platform, we tested thermal cycling with simple heating and natural cooling on chip with water and, heating rates (5°C/s when heating, 3°C/s when cooling) are obtained. Therefore, the COC microfluidic platform can be applied to a DNA lab-on-a-chip.
A novel polymer microfluidic device for self-wash using only capillary force is presented. A liquid filled in a reaction chamber is replaced by another liquid with no external actuation. All the fluidic actuations in the device is pre-programmed about time and sequence, and accomplished by capillary force naturally. Careful design is necessary for exact actions. The fluidic conduits were designed by the newly derived theoretical equations about the capillary stop pressure and flow time. Simulations using CFD-ACE+ were conducted to check the validity of theory and the performance of the chip. These analytic results were consistent with experimental ones. The chip was made of polymers for the purpose of single use and low price. It was fabricated by sealing the hot-embossed PMMA substrate with a PET film. For simpler fabrication, the chip was of a single height. The embossing master was produced from a nickel-electroplating on a SU8-patterned Ni-plate followed by CMP. The contact angles of liquids on substrates were manipulated through the mixing of surfactants, and the temporal variations were monitored for a more exact design. The real actuation steps in experiment revealed the stable performance of selfwash, and coincided well with the designed ones. The presented microfluidic method can be applicable to other LOCs of special purposes through simple modification. For example, array or serial types would be possible for multiple selfwashes.