A graphene-based electrochemical device with thermoresponsive microneedles for diabetes monitoring and therapy

Abstract

Owing to its high carrier mobility, conductivity, flexibility and optical transparency, graphene is a versatile material in micro- and macroelectronics. However, the low density of electrochemically active defects in graphene synthesized by chemical vapour deposition limits its application in biosensing. Here, we show that graphene doped with gold and combined with a gold mesh has improved electrochemical activity over bare graphene, sufficient to form a wearable patch for sweat-based diabetes monitoring and feedback therapy. The stretchable device features a serpentine bilayer of gold mesh and gold-doped graphene that forms an efficient electrochemical interface for the stable transfer of electrical signals. The patch consists of a heater, temperature, humidity, glucose and pH sensors and polymeric microneedles that can be thermally activated to deliver drugs transcutaneously. We show that the patch can be thermally actuated to deliver Metformin and reduce blood glucose levels in diabetic mice.

A skin-attachable, stretchable integrated system based on liquid GaInSn for wireless human motion monitoring with multi-site sensing capabilities

“…In the case of a strain sensor, when wireless transmission functions, including power and data transfer, are not incorporated, a hard wire connection is required with an external measuring device, which degrades the durability of the device and significantly limits the user's activity when worn. Recent work demonstrates various wireless chemical and biological sensor systems with Bluetooth 23,24 and near-field-communication (NFC) [25][26][27] capabilities, the latter of which can also be operated in a battery-free mode via power harvesting. However, previously reported liquid metal-based antennas tend to be unsuitable for skin-attachable applications in terms of size or thickness, mostly because of limitations in the injection method.…”

Autonomous sweat extraction and analysis applied to cystic fibrosis and glucose monitoring using a fully integrated wearable platform

“…Despite significant progress made in printed and flexible biosensors in the field, a majority of wearable devices focus on monitoring of physical activity or selected electrophysiological parameters, providing only limited information regarding physiological changes of complex homeostatic responses (4)(5)(6)(7)(8)(9)(10). Wearable chemical sensors offer great opportunities for collecting physiological information at the molecular level (3,(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Recently research advances have resulted in a variety of wearable sweat sensors that can be used for real-time analysis of sweat biomarkers including electrolytes, metabolites, and heavy metals (11)(12)(13)(14)(15)(16)(17)(18)(19)(20).…”

“…Wearable chemical sensors offer great opportunities for collecting physiological information at the molecular level (3,(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Recently research advances have resulted in a variety of wearable sweat sensors that can be used for real-time analysis of sweat biomarkers including electrolytes, metabolites, and heavy metals (11)(12)(13)(14)(15)(16)(17)(18)(19)(20). We recently demonstrated a fully integrated wearable sensing system for real-time monitoring of multiple analytes in human perspiration during physical exercise which allows accurate measurement of sweat analytes through signal processing and calibration (16).…”

Designing the Health-related Internet of Things: Ethical Principles and Guidelines

“…Wearable, embedded and implantable sensors can be used to monitor a variety of physiological parameters and behaviours. Semi-permanent sensors can also be woven into clothes or wristbands for physiological measurements, including detection of specific molecules in perspiration [114,115] or motion metrics to monitor Parkinson's disease [116]. Software updates and applications can also turn existing devices into wearable monitors, as shown with health monitoring smart phones application that can track exercise or movement and share data with health professionals and other third parties [117,118].…”