3D-Printed and Wearable Surface Reflectance Sensor

Three-dimensional (3D) printing has been recently adopted in the fields of textiles and electronics. Already, technologies have been introduced for 3D-printed electronics, which resemble rigid and flexible electronics. In textiles, deformable electronics have been used for compliant and easily integrable electronics, which 3D printing has not been focused on. In this work, a compliant and wearable 3D-printed sensor is manufactured and demonstrated. A programmable surface reflectance and brightness sensor was made packaged with a thermoplastic polyurethane (TPU) matrix, stretchable silver ink, and off-the-shelf electronic components. The range of measured surface reflectance values of colored and grayscale surfaces cover ~79% and ~82% of the sensing range of the sensor, correspondingly. The quality of results is verified by confirming the linearity of results against spectrophotometer values. The sensor is demonstrated by integrating it into clothing, where the sensor detected variations in environment brightness.