Microfabricated recessed disk microelectrodes: characterization in static and convective solutions

• US 20030015422A1
• Filed: 03/22/2002
• Published: 01/23/2003
• Est. Priority Date: 04/30/1997
• Status: Active Grant

• Current Assignee: The Board of Trustees of the University of Arkansas (University of Arkansas System)
• Original Assignee: The Board of Trustees of the University of Arkansas (University of Arkansas System)
• Inventors: Fritsch, Ingrid, Henry, Charles Sherman, Bowen, Benjamin P., Vandaveer, Walter, Bratcher, Nicole
• Granted Patent: US 7,169,272 B2
• Time in Patent Office: Days
• US Class Current: 204/403.01
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G01N 27/3278 involving nanosized elements, e.g. nanogaps or nanoparticles nanopores G01N33/48721; magnetic beads G01N27/745

Abstract

Construction and characterization of microfabricated recessed disk microelectrodes (RDMs) of 14 and 55 μm diameter are reported. The work reported here makes several new contributions to the current literature on microfabricated RDMs. Hybrid blamers were constructed by fusion of vesicles of dimyristoylphosphatidyl choline (DMPC), which forms the top layer, with ethanol-rinsed SAMs of hexadecanethiol on gold, which form the bottom layer. Gramicidin A was included in the modifying solutions to incorporate it into hybrid blamers.

Claims

1. A 3-dimensional microfabricated device wherein edges of a lipid bi-layer are anchored by alknethiol derivitized inner edges of Au layers in an etched region of insulator and wherein a bottom of the device is lined with an insulator layer.

2. The 3-dimensional microfabricated device of claim 1 having a hole in said bottom for minimizing osmotic effects.

3. The 3-dimensional microfabricated device of claim 1 having a multiple well array.

4. A method for microfabricating recessed disk microelectrodes comprising:

growing a silicon dioxide film on a silicon wafer by thermal oxidation;

spin-coating said silicon wafer with positive photoresist;

exposing said silicon wafer to ultra violet light through a photolithographic mask;

developing said photoresist and leaving a pattern of parallel lines, which are contact leads and microdisk electrodes;

depositing a chromium filled adhesion layer on said photo resist by thermal evaporation;

sonicating said wafer in acetone to dissolve the photoresist and to cause lift-off of said metal on top of said wafer;

drying said wafer;

spin-coating said wafer with polyimide;

polymerizing said polyimide by exposure to ultraviolet light and curing said

polyimide to cross-link a polymer thereby formed;

depositing a second chromium layer on top of said polyimide by thermal evaporation;

spin coating said wafer with positive photoresist;

patterning said photoresist by exposure to ultraviolet light through a second photolithographic mask;

simultaneously etching the second gold layer and the second chromium layer with aqua regia;

stripping a remainder of photoresist with acetone;

drying said wafer;

leaving a covering of gold and chromium covering electrode lines with an area over an end of lines left open for contact purposes; and

forming a hole through said second layer of golden chromium, and through said polyimide layer to expose said first layer of gold and chromium.

5. A microfabricated recessed disk microelectrode produced by the process of claim 4.