Tissue‐Adhesive Piezoelectric Soft Sensor for In Vivo Blood Pressure Monitoring During Surgical Operation

Abstract

The reliable function in vivo of self‐powered implantable bioelectric devices (iBEDs) requires biocompatible, seamless, effective interactions with biological tissues. Herein, an implantable tissue‐adhesive piezoelectric soft sensor (TPSS), in which the piezoelectric sensor converts biomechanical signals into electrical signals, and the adhesive hydrogel (AH) strengthens this conversion by seamlessly adhering the sensor on the wet and curvilinear surface, is proposed. The optimized AH exhibits strong adhesion to various organic or inorganic surfaces, including six commonly used engineering materials and three biological tissues. As a pressure sensor, TPSS proves good in vitro electrical performance with a high output of 8.3 V, long‐term stability of over 6000 cycles, and high energy power density of 186.9 µW m−2. In a large animal experiment, TPSS seamlessly adheres to the right‐side internal carotid artery of a Yorkshire pig to monitor blood pressure during a surgical operation. Compared to commercial sensors that work by inserting into tissues, TPSS does not cause any damage and can be peeled off after service. The integration of adhesive hydrogel and self‐powered pressure sensors enables biocompatible, seamless, and more efficient interactions between the biological system and iBEDs, which also contributes to next‐generation implantable bioelectronics with features of battery‐free, intelligent, and accurate.

Soft Sensors and Actuators for Wearable Human–Machine Interfaces

“…168 In particular, intimate attachment to the skin reduces noise from dynamic body motion and allows for long-term adhesion to curved and complex surface. This enables advanced medical and clinical applications, such as enhanced monitoring of weak biosignals like biopotential and blood flow, 99,165,169,170 intensive and optimized therapy, 171 and analyte collection. 166 Furthermore, skin conformity provides spatio-termporal recognition, 172 precise encoding/decoding tactile signal, 62,164 and intensive actuating feedback, 9 which enhances the user experience in HMI applications.…”

Advancements in Bio-inspired Self-Powered Wireless Sensors: Materials, Mechanisms, and Biomedical Applications

“…This output voltage matching the systolic and diastolic pressure measured by the sphygmomanometer was able to detect in vivo blood flow to determine the irregularities caused by thrombosis. In another example, Wang et al 280 integrated an implantable piezoelectric biosensor with an adhesive hydrogel inspired by the adhesive behavior of mussels in seawater. This PVDF film-based biosensor sensitive to continuous dynamic bending was used to convert pressure signals into electrical signals, while the adhesive hydrogel enhanced this conversion by seamlessly adhering the sensor to a curved and wet surface.…”

Perspectives on recent advancements in energy harvesting, sensing and bio-medical applications of piezoelectric gels

“…Piezoelectric hydrogels with exceptional structural functionality and highly programmable properties have accelerated the development of sensing devices. 147,267–276 Tian and coworkers recently developed a self-powered motion sensor comprised of PHEMA, graphene oxide (GO), and single-walled carbon nanotubes (SWCNTs). 267 The degree of piezoelectricity and sensing properties of the nanocomposite hydrogel was determined by the surface area of the GO and the high strength of the SWCNTs.…”

“…In 2023, Lee and coworkers employed a PVDF-based composite hydrogel tissue-adhesive piezoelectric soft sensor (TPSS) to develop in vivo self-powered implantable bioelectric devices for pressure sensing. 269 As a pressure sensor, the TPSS displayed high output voltage of 8.3 V and a high energy power density of 186.9 μW m −2 . In addition, the composite hydrogel sensor demonstrated robust adherence to a variety of engineering materials and biological tissues.…”