Ultra-Low-Cost Integrated Silicon-based Transducer for On-Site, Genetic Detection of Pathogens

Estefania Nunez-Bajo; Michael Kasimatis; Yasin Cotur; Tarek Asfour; Alex Collins; Ugur Tanriverdi; Max Grell; Matti Kaisti; Guglielmo Senesi; Karen Stevenson; Firat Guder

Because Si has a high thermal conductivity (~150 W m -1 °K -1 at 300 °K), the substrate can be heated uniformly regardless of the path the current flows. The electrical resistance of Si also varies with temperature with a negative correlation (within our experimental range of temperatures from RT to 110 °C); the electrical resistance of Si drops with increasing temperature due to generation of mobile charge carriers allowing the use of Si substrate itself as a sensitive sensor of temperature. [20] [21] [22] We have applied electrical currents in the range 0-400 mA between two Au electrodes deposited on the bottom of TriSilix chip to heat up the device electrically (the experiments were performed at room temperature; ~25 °C). During this experiment, we used a thermal camera (FLIR E4) to measure the temperature across the chip as a reference measurement. As illustrated in Figure 3A , TriSilix chip can be heated up to 110 °C, electrically. The relationship between the current applied and substrate temperature was linear (with a positive slope) at steady-state with high repeatability (slope: 232.3±8.7 °C A -1 ; R 2 = 0.9971, N=5).