Integrated Electrochemical Sensors and Actuators for Multifunctional Surgical Endoscope and Glucose Monitoring System

Abstract

Over the past decade, flexible and stretchable electronics have achieved remarkable progress with regard to materials, designs, and manufacturing processes for biomedical applications. The electronics resolve the intrinsic mechanical mismatch between the devices and soft/curvilinear biological substrates. This enables a wide range of applications in noninvasive, minimally invasive, and wearable devices. This dissertation includes two examples of multifunctional, flexible, and stretchable electronic systems for biomedical applications, especially in dealing with colon cancer and diabetes. First, the multifunctional endoscope system is introduced as a minimally invasive surgical tool for colon cancer treatment. Transparent bioelectronics based on a graphene hybrid are fabricated for impedance- and pH-based colon cancer detection. Bioelectronics can ablate colon cancer by using radio frequency as a feedback therapy. The bioelectronics placed in the endoscope can provide both characterization and treatment of colon cancer without optical hindrance. Second, wearable and/or disposable sweat monitoring devices with microneedle-based transdermal drug delivery devices are developed for noninvasive blood glucose control. The glucose in sweat is correlated with the glucose in blood, which enables sweat-based blood glucose monitoring. The sensors monitor the sweat glucose concentration with a correction based on pH, temperature, and humidity measurements for accurate sensing. A thermoresponsive microneedle with drug loading is integrated for controlled transdermal drug delivery when hypoglycemia occurs. The dissertation herein provides two representative examples of a multifunctional system as the basis for a closed-loop solution from disease monitoring to treatment. In-vitro, ex-vivo, and in-vivo experiments highlight the utility of the demonstrated technologies for colon cancer and diabetes treatment.