Surface plasmon based thermo-optic and temperature sensor for microfluidic thermometry

TL;DR

This paper introduces a surface plasmon resonance-based method for precise, non-invasive thermal characterization of microfluidic liquids, achieving high accuracy with minimal sample volume and simple apparatus.

Contribution

It presents a novel, low-power, single-wavelength surface plasmon sensor for accurate thermo-optic and temperature measurements in microfluidic fluids.

Findings

Determined thermo-optic coefficients with accuracy better than 10^{-5} 1/°C

Achieved temperature sensing accuracy of 0.03 °C

Suitable for integration into lab-on-chip systems

Abstract

We report on a non-interacting technique for thermal characterization of fluids based on surface plasmon resonance interrogation. Using liquid volumes less than 20 micro liters we have determined the materials' thermo-optic coefficients with an accuracy of better than 10^{-5} 1/{\deg}C and demonstrated temperature sensing with an accuracy of 0.03 {\deg}C. The apparatus employs a low-power probe laser, requiring only a single wavelength, polarization and interrogation angle for accurate characterization. The device is particularly suited for precise diagnostics of liquids and gases within microfluidic systems, and may also be readily integrated into a variety of lab-on-chip platforms, providing rapid and accurate temperature diagnostics.