Karem Lozano Montero; Yayun Du; Ninja Kajas; Jacob Trueb; Mikko Peltokangas; Hany Arafa; Jin-Tae Kim; Jianyu Gu; Remmi Calvo Guzman; Niku Oksala; Jiantong Li; Antti Vehkaoja; John A. Rogers; Matti M盲ntysalo; Mika-Matti Laurila (2026).听.听Advanced Sensor Research, 5(3), e00145.听
聽聽This study presents a non-invasive system for monitoring pulse waves using a soft, skin-like sensor combined with a wireless data unit. The system includes an聽electronic tattoo (e-tattoo)鈥攁 very thin, flexible sensor that can stick to the skin鈥攁nd a small, stretchable data transmission unit (DTU) that contains a rechargeable battery, Bluetooth for wireless communication, and electronics to process the signal. The e-tattoo is made using a simple printing process and uses聽ferroelectric materials聽(materials that generate an electrical signal when mechanically stressed) to detect subtle pulse vibrations from the body.
The researchers improved the system鈥檚 performance in several ways. By carefully choosing the electrode materials in the e-tattoo, they greatly increased the accuracy of pulse measurements, reducing error in one key timing metric (the 鈥渞elative crest time index,鈥� which reflects how quickly blood pressure waves rise) from over 50% to nearly zero. They also enhanced the sensor鈥檚 sensitivity鈥攊ts ability to detect small forces鈥攂y integrating it with the soft outer layer of the DTU, boosting its response from 25 to 1277 picocoulombs per newton (a measure of electrical output per applied force). Finally, they demonstrated that the system can successfully measure meaningful clinical indicators from the radial artery (at the wrist) in a human subject. Overall, this work shows that wearable, skin-like electronics can provide accurate, wireless monitoring of cardiovascular signals in a comfortable and practical way.
FIGURE 1
a) An exploded view of the proposed wireless and soft pulse wave measurement device comprising the DTU and the ferroelectric/piezoelectric e-tattoo sensor, and b) Effect of curing temperature on polarization vs. electric field loop of P(VDF-TrFE) samples (n = 3). Range bars show the min and max polarization values for each data point.