To save half contact pads in 2D mapping of local temperatures with a thermocouple array

The rapid development of micro-electronic devices requires smaller sensors with better sensitivity and higher spatial resolution than what could be obtained from sensors currently available. For a two-dimensional (2D) mapping of local temperatures with thin-film thermocouple (TFTC) arrays, a higher spatial resolution usually means a larger amount of sensors in the array, which always leads to more leads and contact pads. We demonstrated here that by using a tree-like array, where all the leads of one material shared a common contact pad, an array consisting of N TFTCs could perform well with only N + 1 contact pads rather than 2N pads for the conventional configuration, resulting in the same 2D maps of local temperature distribution as those measured with a conventional array. The relative error was less than 5%. This simplified device configuration has efficiently reduced the difficulty in wire bonding and device fabrication, therefore it may find applications in novel wearable and flexible devices.