Reliability Assessment and Multiphysics Simulation of Additively Printed Wearable Humidity Sensor With Supercapacitive Material for Astronaut in Extreme Condition

Abstract

Additive technologies, such as aerosol jet printing (AJP) and direct write printing, are increasingly being used in the production of printed circuit boards because they eliminate the need for costly tooling, such as photomasks or etching containers. This is because additive methods allow for the direct deposition of printing materials onto a substrate. A design and manufacturing approach based on software also enables production flexibility, as well as speedier tool adjustments and design development. Moreover, additive printing methods could be used on a wide range of materials, including fabrics, vehicles, and polymers with various surfaces and forms. This versatility in a broad variety of applications allows engineers to create diverse applications, such as sensing devices with electro-cardiogram sensors, pulse-oxygen sensors, galvanic skin response sensors, body temperature sensors, humidity sensors, and so on. Due to its potential for adaptability and integration, the development of additively printed humidity sensors has been the subject of several prior investigations. There are still issues with the reliability of current humidity sensor technology when flexing force is coupled with the humidity sensor. For the avoidance of stability issues, it is required to develop a better printing technique, process recipe, and sensing material encapsulation. In this research, the direct-write (D-write) printing approach with an nScrypt printer was employed to print the humidity sensor as a test vehicle in a laboratory setting. The sensor was characterized by analyzing the print recipe and its interaction with humidity in regard to resistance and humidity sensitivity. Additionally, the characterization of sensor accuracy, hysteresis, linearity, and stability in relation to temperature and humidity variation has been measured. Furthermore, a multiphysics simulation model was created in order to comprehend the electrochemical processes that occur when the humidity sensor is exposed to a very humid environment.