Integration of Three-Dimensional Silicon Microtip Arrays onto Flexible Substrates
Abstract
Three-dimensional (3D) microelectrode arrays with vertical probes offer important opportunities for not only electrically recording electrical impulses in the electrically excitable cells or tissues but stimulating neurons with electrical impulses from an external source. Recently, emerging micro/nano-fabrication techniques, such as photolithography, electron beam lithography, etc., enable to create precisely engineered nanoscale tip-based probes, allowing to efficiently access deep into tissues or cells to improve electrical coupling in a minimally invasive manner. Notable examples include the mushroom-shaped microelectrodes for intracellular recordings from Aplysia neurons and mammalian cell lines, pyramid-shaped micro-cones for intracortinal mapping and stimulating, and sharp needle-like arrays (often referred to as Utah arrays) for improved electrical coupling between electrodes and biosystems. These arrays are built on rigid and inflexible wafer-based platforms, which are designed to be suitable for the existing micro/nano-fabrication techniques. These mechanical properties of such vertical sensor arrays yield non-conformal contacts to the curvilinear surfaces of the target biological systems, leading to low-fidelity electrical coupling and increased potential to cause damages to cells, especially when used chronically. A key challenge remains in the ability to overcome the mechanical mismatch between the rigid, planar platforms of the vertical sensor arrays and the soft, curvilinear surfaces of biological systems. This project aims to identify a collection of optimized structural designs and novel fabrication strategies that are capable of integrating arrays of vertical Si nanotip-based probes onto flexible, biocompatible substrates such as polyimide. We fabricated vertical arrays of nanotips on a Si wafer with nanoscale textures that can enhance the interfacial interactions with biological cells at the nanoscale.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 25, 2018
- Accession Number
- AD1077269
Entities
People
- Chi H. Lee
- Dong R. Kim
Organizations
- Purdue University