Fully Printed Temperature Sensor Array Comprising 625 60×60 µm 2 pixels

Abstract

With further digitalization and automation, new applications fields require new solutions and sensors. Healthcare, soft robotics, and battery research are only three examples striving for sensor solutions capable of measuring the spatial and temporal temperature distribution of surfaces. This requires the deposition of multiple sensor pixels with a high spatial resolution on potentially flexible substrates. Printing technologies are well suited to fulfill the associated requirements of quality, speed, feature size, and costs. Combining screen printing and aerosol jet printing allows for fast large‐scale processing and when needed high‐precision fabrication for small features. The presented high‐density temperature sensor array provides 625 sensor pixels with a size of 60×60 µm 2 , evenly distributed over an area of 12×12 mm 2 . The sensor is operated without encapsulation between 5 and 90 °C showing an average deviation of less than 0.5 °C. The sensor stack consists of a bottom and top electrode sandwiching a carbon black based thermistor layer. The material shows a strong negative‐temperature‐coefficient (NTC) effect with a sensitivity of 3.6 % °C −1 at 5 °C. As an application example, the temperature profile induced by a laser beam is mapped with the temperature sensor array.