Potentially Low-Cost and Transparent Sensor Array Systems for Cellular Monitoring and Smart Skin Applications

Technology

The invention is a sensor array accompanied by a custom circuit board for monitoring chemical or electrical activity, which is both compatible with optical equipment and is readily scalable. One application of this innovation is in monitoring cellular activity. The sensor array substrate and wires are all fabricated out of transparent materials, ensuring compatibility with optical equipment. The graphene Electrolyte-Gated Field-Effect Transistor (EGFET) array architecture was developed with a compact, inexpensive and self-contained measurement system capable of performing DC characterization of 256 graphene EGFETs. This enables optimization of the transistor gain, resulting in a highly sensitive sensor array. In addition, a framework for application-specific optimization of large-scale graphene EGFET sensor designs was developed. The manufacture process is both simple and cost effective. Once fabricated, the sensor array can be inserted into the custom circuit board, containing analog multiplexers for row and column selection, signal manipulation circuitry for cellular monitoring, and input ports for data acquisition and microcontrollers.

Problem Addressed

Recently, sensor technology utilizes wire sharing with integrated semiconductor materials for systems requiring large arrays of sensors. These systems use silicon thin films, which are flexible; however, the process of making the films is expensive and adds complexity to the fabrication process. The technology relies on silicon, which is opaque, making it ill-suited for optical applications including compound microscope imaging. In addition, current designs have not maximized the gain and minimized gain variations, which are both important for optimizing the performance of gated sensor arrays in large-scale sensor systems.

Advantages

• Simple, inexpensive sensor array compatible with optical equipment
• Highly sensitive sensor arrays due to optimized gain in EGFETs
• Can be fabricated on flexible polymer substrates

Publications

Kuzum, D., et al. "Transparent and Flexible Low Noise Graphene Electrodes for Simultaneous Electrophysiology and Neuroimaging." Nature Communications 5 (2014): 5259. doi: 10.1038/ncomms6259.

Viventi, J., et al. "Flexible, Foldable, Actively Multiplexed, High-Density Electrode Array for Mapping Brain Activity in Vivo." Nature Neuroscience 14 (2011): 1599–1605. doi: 10.1038/nn.2973.