FEEDBACK CONTROL OF DIMENSIONS IN NANOPORE AND NANOFLUIDIC DEVICES

• US 20160355943A1
• Filed: 08/20/2016
• Published: 12/08/2016
• Est. Priority Date: 11/02/2010
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Harrer, Stefan, Rossnagel, Stephen M., Waggoner, Philip S.
• Granted Patent: US 10,323,333 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B81C 1/00071 Channels
• CPC Class Codes: B81C 2201/0114 Electrochemical etching, anodic oxidation
• CPC Class Codes: C25D 9/06 by anodic processes

Abstract

Nanofluidic passages such as nanochannels and nanopores are closed or opened in a controlled manner through the use of a feedback system. An oxide layer is grown or removed within a passage in the presence of an electrolyte until the passage reaches selected dimensions or is closed. The change in dimensions of the nanofluidic passage is measured during fabrication. The ionic current level through the passage can be used to determine passage dimensions. Fluid flow through an array of fluidic elements can be controlled by selective oxidation of fluidic passages between elements.

Claims

1. A method comprising:

providing a substrate comprising a nanofluidic passage bounded by an electrical conductor;

filling the nanofluidic passage with an electrolyte;

causing the nanofluidic passage to at least partially close by electrochemically forming an oxide layer on the conductor; and

setting a target dimension for the nanofluidic passage, monitoring the size of the nanofluidic passage, and discontinuing causing the nanofluidic passage to at least partially close when the target dimension is reached; and

wherein the nanofluidic passage is a surface channel in the substrate.

2. A method comprising:

forming a nanofluidic passage having larger than targeted dimensions in a substrate;

forming a conductive layer on the substrate, thereby reducing the dimensions of the nanofluidic passage,

filling the nanofluidic passage with an electrolyte; and

electrochemically oxidizing the conductive layer until the fluidic passage has the targeted dimensions;

wherein the nanofluidic passage is a channel.

3. The method of claim 2 wherein the channel is formed with an opening in a surface of the substrate, further including the step of closing the opening when forming the conductive layer on the substrate.

4. A computer program product for controlling the fabrication of a nanofluidic device including a nanofluidic passage in a substrate, the nanofluidic passage comprising an electrically conductive surface and containing an electrolyte:

a computer readable storage medium having computer readable program code embodied therewith, said computer readable program code comprising;

computer readable program code configured to facilitate applying an electric potential between the electrolyte and the electrically conductive surface sufficient to cause oxidation of the electrically conductive surface;

computer readable program code configured to monitor ionic current through the nanofluidic passage.

5. The computer program product of claim 4, further comprising computer readable program code configured to continuously monitor ionic current as the conductive surface is oxidized.

6. The computer program product of claim 4, further comprising computer readable program code configured to alternatively monitor the ionic current and apply the electric potential between the electrolyte and the conductive surface until a desired nanofluidic passage size is reached.

7. A method comprising:

providing a nanofluidic device including a nanofluidic passage having an electrically conductive surface and an electrolyte within the nanofluidic passage;

applying a voltage to the electrically conductive surface to electrochemically change the dimensions of the nanofluidic passage; and

reducing the dimensions of the nanofluidic passage by oxidizing the electrically conductive surface.