No abstract

Evaluation of the oxygen‐mediated effects of clinical and daily activities demands an on‐skin device that can track multi‐vital regional tissue hemodynamics simultaneously. For example, peripheral arterial disease (PAD) is the third most prevalent cardiovascular disease, but the means of diagnosing and monitoring this disease are limited because the affected area is usually in the non‐pulsatile area away from the heart. Herein, we report on an ultrathin and ultralight multi‐vital near‐infrared optoelectronic biosensor for the diagnosis and rehabilitation monitoring of regional tissue hemodynamics, which is suitable for mounting on the skin for long‐term measurement. The device can simultaneously detect tissue oxygen saturation, heart rate, arterial blood oxygen, and tissue perfusion and shows potential for various hypoxia monitoring applications. Moreover, the tissue hemodynamics detected by this device showed a highly accordance with the ankle‐brachial index and CT angiography obtained by traditional clinical methods. Therefore, our design was able to accurately diagnose and effectively evaluate PAD patients before and after surgery. The on‐skin optoelectronic biosensor shows potential in biological oxygen‐mediated behavior evaluation, injury‐state monitoring, PAD clinical diagnosis optimization, and after surgery care.

Flexible pressure sensors that emulate the sensation and characteristics of natural skins are of great importance in wearable medical devices, intelligent robots, and human–machine interfaces. The microstructure of the pressure-sensitive layer plays a significant role in the sensor’s overall performance. However, microstructures usually require complex and costly processes such as photolithography or chemical etching for fabrication. This paper proposes a novel approach that combines self-assembled technology to prepare a high-performance flexible capacitive pressure sensor with a microsphere-array gold electrode and a nanofiber nonwoven dielectric material. When subjected to pressure, the microsphere structures of the gold electrode deform via compressing the medium layer, leading to a significant increase in the relative area between the electrodes and a corresponding change in the thickness of the medium layer, as simulated in COMSOL simulations and experiments, which presents high sensitivity (1.807 kPa−1). The developed sensor demonstrates excellent performance in detecting signals such as slight object deformations and human finger bending.