Portable Temperature-Controlled System Integrating Thin-Film Sensors and Actuators for Biochemical Analysis on Transparent Substrate

This work presents a portable system developed to perform biochemical analyses requiring both temperature sensing for the thermal sample treatment and optical sensing to detect the analyte. To achieve this goal, we coupled a system-on-glass, hosting on a single glass substrate a thin film transparent heater and two temperature sensors, with interface electronics able to drive the heating source and control the temperature. The system-on-glass has been optimized to ensure temperature uniformity better than ±1.4 °C over a large-area (6 cm2) and sensor resolution better than 0.01 °C. Moreover, the presented device operates at a remarkably low power of only 2.4 W/cm2 to achieve a temperature of 100 °C, significantly below the power requirements of most comparable devices available on the market. The electronics has been designed to minimize electromagnetic interferences between the heater and the biological samples. The temperature-controlled platform has been enclosed in a 3D-printed black resin-made box whose dimensions are 11 cm · 10 cm · 2.4 cm, while the electronics is enclosed in a metallic box (12.55 cm · 8.05 cm · 4.32 cm), connected with the 3D-printed box by an Ethernet cable. The compactness and low weight (below 0.5 kg) of the two boxes ensures the system portability while the easy coupling of the system-on-glass with different kinds of microfluidic networks allows its employment for a large variety of biosensing applications.