Emerging Biomedical Devices with Novel Materials: Transparent Graphene Neural Electrodes and Electrochemical Aptamer Sensors

Date(s) - 05/17/2017
3:00 pm

Dong-Wook Park, Ph.D., Postdoctoral Research Fellow, Stanford University


The innovation of biomedical devices could start from the understanding of novel materials and underlying device physics. Unique biological studies with the emerging devices and systems could open new possibilities to diagnose and cure diseases. In this talk, two emerging biomedical devices and their utilities to in vivo and ex vivo studies will be discussed.

Transparent graphene neural electrodes: Previous in vivo studies with conventional metal-based sensors were limited to monitoring the tissue surrounding the electrode sites due to the opaqueness of the metal. Optical stimuli through the electrode sites and traces were also impossible with metal brain sensors. Graphene, a novel material made of carbon atoms, has broad wavelength transparency from ultraviolet (UV) to infrared (IR) enabling unique in vivo experiments. The transparent graphene neural electrodes implanted over the cerebral cortex in rodents allowed for chronic investigations of the underlying neural tissue while simultaneously performing electrophysiology. In vivo imaging of the cortical vasculature through the transparent brain sensor has been shown via fluorescence microscopy and 3D optical coherence tomography. Optogenetic activation of focal cortical areas directly beneath electrode sites has been demonstrated in transgenic Thy1::ChR2 mice. Electrical stimulation through graphene electrodes and its simultaneous monitoring was also viable.

Electrochemical aptamer sensors: Aptamers are single-stranded DNA or RNA or XNA that bind to specific molecular targets with high affinity and specificity. Aptamer-based electrochemical sensors that could monitor various biomolecules have been developed upon the implantable neural electrodes technology. These next-generation biomedical devices would help improve the diagnosis and treatment systems.

Bio: Dr. Dong-Wook Park is a Postdoctoral Research Fellow at Stanford University with a joint appointment in the department of Electrical Engineering (School of Engineering) and Radiology (School of Medicine). He received his Ph.D. degree in electrical and computer engineering at the University of Wisconsin-Madison where he studied implantable neural electrodes. Prior to joining the University of Wisconsin-Madison in 2011, he was at Samsung Display R&D center as a circuit design engineer. His current research centers on emerging biomedical devices and systems based on novel materials and nanotechnologies.