Commercially available Total Phosphorus (TP) analysis systems offer good sensitivity and accuracy but suffer from drawbacks such as large size, complex pretreatment processes, and high cost. Traditional systems require a pretreatment step involving heating the fluidic analyte to 120°C for 30 minutes to release dissolved phosphate, which poses challenges in miniaturization due to elevated pressures and temperatures. We employ a photocatalytic reaction in the pretreatment process, utilizing a microfluidic channel with a photocatalytic titanium dioxide (TiO2) surface illuminated by ultraviolet (UV) light. Unlike conventional methods, this simplified, photocatalytic-reaction-based pretreatment process eliminates the need for elevated temperatures and pressures, providing greater flexibility in designing and fabricating LOC devices for TP monitoring.

The conventional biosensors have challenges such as low throughput and signal-to-noise ratio. we propose a microfluidic chip with multiple detection gates to enhance the throughput while maintaining a simple operational system. A hydrodynamic sheathless particle focusing on a detection gate by modulation of the channel structure and measurement circuit with a reference gate to minimize the noise during detection is used for detecting resistive pulses. The proposed microfluidic chip can analyze the physical properties of 200 nm polystyrene particles and exosomes from MDA-MB-231 with high sensitivity with an error of <10% and high-throughput screening of more than 200,000 exosomes per second. The proposed microfluidic chip can analyze the physical properties with high sensitivity so that it can be potentially used for exosome detection in biological and in vitro clinical applications. 

Flip-chip microbump bonding technology between InP and SiC substrates for a millimeter-wave wireless communication application is demonstrated. The proposed process of flip-chip μ-bump bonding to achieve high-yield performance utilizes a SiO2-based dielectric passivation process, a sputtering-based pad metallization process, an electroplating bump process enabling a flat-top μ-bump shape, a dicing process without the peeling of the dielectric layer, and a SnAg-to-Au solder bonding process. By using the bonding process, 10 mm long InP-to-SiC coplanar waveguide lines with 10 daisy chains interconnected with a hundred μ-bumps are fabricated. All twelve CPW lines show uniform performance with insertion loss deviation within ±10% along with an average insertion loss of 0.25 dB/mm, while achieving return losses of more than 15 dB at a frequency of 30 GHz, which are comparable to insertion loss values of previously reported conventional CPW lines. In addition, an InP-to-SiC resonant tunneling diode device is fabricated for the first time and its DC and RF characteristics are investigated.