Crosstalk-free hybrid integrated multimodal sensor for human temperature, humidity, and pressure monitoring

<h2>Summary</h2> Current developments in flexible sensors for epidermal pressure monitoring lack a fully integrated multimodal solution due to challenges such as crosstalk and complex integration processes. Here, a crosstalk-free multimodal sensor is presented by simple vertical lamination and spraying. Except for integrating the multimodal sensor, the device is equipped with a signal conditioning circuit, enhancing its portability. Importantly, each sensor is sensitive only to its specific stimulus but not to other stimuli, enabling signal decoupling without complex algorithms. The pressure sensor exhibits enhanced sensitivity (eight times greater than unstructured designs), and the temperature sensor shows a high sensitivity of 60.64 Ω/°C and a linearity of <i>R</i>² = 0.9982 below 160°C. Meanwhile, the capacitance of the humidity sensor varies by 72 pF as humidity increases from 15% to 95%. The high integration and simple fabrication process provides a promising design concept for application in pressure ulcer prevention and telemedicine.