Evaluation of Patchable Inkjet-printed Wearable Sensors for Measuring Muscle Activities

In this paper, we present a patchable, non-invasive, inkjet-printed wearable electromyography sensor designed for unobtrusive, comfortable, and long-duration use. It will offer a compact, low-cost solution while maintaining high signal quality and resistance to body movement. As a first step toward creating practical, everyday wearable sensors, we conducted human-in-the-loop experiments with six participants, comparing the usability and performance of the proposed sensor against two existing commercial electromyography sensors during isometric and non-isometric contractions. We evaluated four key metrics-signal-to-noise ratio, signal-to-motion artifact ratio, drop in power density ratio, and power spectral density-against those of conventional sensors to assess the sensor's effectiveness and reliability. Additionally, user experience surveys were conducted to inform improvements in both the functional and emotional design aspects, with a focus on enhancing comfort and overall usability.