Large-Area Thin Film Heater for Thermal Treatments in Lab-on-Chip

This work reports on the development of a large-area thin film heater for lab-on chip applications. The device is a chromium/aluminum/chromium stacked structure with a spiral shape fabricated on a $5\times 5\text{cm}^{2}$ glass substrate through microelectronic technologies. Its geometry has been designed and optimized by COMSOL Multiphysics in terms of pitch and line width to achieve a uniform temperature distribution. Measurements performed with a thermo-camera show temperature variation below 1.5°C over 5cm2 area in excellent agreement with numerical modeling. To our knowledge, this is the largest area with such temperature uniformity achieved with a single heater in lab-on-chip systems. This opens the route for large-area thermal treatments as multiple-well DNA amplification or cell culture.