Titanium Nitride Thin Films and Their Applications in Microfluidic Devices

Tanner Hammonds, Michaelann Tartis, Sanchari Chowdhury

Abstract:

Titanium nitride (TiN) nanoparticles are alternative plasmonic material with low cost and high stability. These materials are of great interest due to their ability to absorb broadband visible to near-infrared regime of solar spectrum and convert that into heat efficiently. In this work, our goal is to develop a photothermal microreactor with TiN nanoparticles thin films coating on the surface. Titanium nitride nanoparticles will absorb light and generate heat required to drive reactions. Specifically, we are developing microfluidic devices suitable for nanoparticle synthesis. We optimized the coating method of nanoparticles on the surface of the reactor to maximize light to heat conversion efficiency. Four layers of a 80 nm TiN nanoparticles solution (10mg/ml) were dip-coated on microscope slides. A silica sol-gel thin film was coated on TiN thin film to prevent the removal of TiN thin films. To demonstrate proof of principle, a simple microfluidic device was fabricated by placing an adhesive layer in between a coated slide and an uncoated slide forming one flow inlet and one flow outlet. We tested the photothermal properties of the microfluidic device using different-intensity broad-spectrum white light (halogen lamp). We could achieve as high as a temperature of 150 °C at the intensity of 833 mW/cm2 on the outer coated side of our device. In summary, we are looking into alternative methods for conducting microreactor experiments via our TiN thin films.