Three-dimensional crystalline, homogeneous, and hybrid nanostructures fabricated by electric field directed assembly of nanoelements

Patent metadata

Field	Value
Publication number	US-11220756-B2
Application number	US-201816131658-A
Country	US
Kind code	B2
Filing date	Sep 14, 2018
Priority date	Jun 29, 2012
Publication date	Jan 11, 2022
Grant date	Jan 11, 2022

Abstract

A variety of homogeneous or layered hybrid nanostructures are fabricated by electric field-directed assembly of nanoelements. The nanoelements and the fabricated nanostructures can be conducting, semi-conducting, or insulating, or any combination thereof. Factors for enhancing the assembly process are identified, including optimization of the electric field and combined dielectrophoretic and electrophoretic forces to drive assembly. The fabrication methods are rapid and scalable. The resulting nanostructures have electrical and optical properties that render them highly useful in nanoscale electronics, optics, and biosensors.

First claim

What is claimed is:

1. A method of fabricating a hybrid nanostructure by electric field directed assembly of nanoelements, the method comprising the steps of:
providing a nanosubstrate comprising a base layer, a conductive layer deposited onto the base layer, and an insulating layer deposited onto the conductive layer, the insulating layer comprising a via, the via forming a void in the insulating layer and defining a pathway through the insulating layer that exposes the conductive layer;
contacting the nanosubstrate with an aqueous suspension of first nanoelements;
applying an electric field between the conducting layer and an electrode in the suspension for a period of time sufficient for migration of first nanoelements from the suspension into the via and their assembly in the via, wherein the electric field consists of the sum of a DC offset voltage and an AC voltage; and
repeating, after the assembly, the contacting and the applying steps, using an aqueous suspension of second nanoelements different from the first nanoelements, thereby obtaining a hybrid nanostructure
wherein the first and second nanoelements are insulating.

2. The method of claim 1 , wherein the nanosubstrate comprises a plurality of vias, and a plurality of hybrid nanostructures are formed.

3. The method of claim 1 , wherein the period of time for migration and assembly is adjusted to obtain a desired height or configuration of the nanostructure.

4. The method of claim 1 , wherein the nanostructure possesses a geometry selected from the group consisting of nanopillars, nanoboxes and nanorings.

5. The method of claim 1 , wherein the first and/or second nanoelements are selected from the group consisting of nanotubes, nanoparticles, and nanowires.

6. The method of claim 5 wherein the nanoparticles are insulating nanoparticles comprising a polymer.

7. The method of claim 1 further comprising fusing the first and/or second nanoelements to form a solid mass by either heating the assembled nanoelements or by applying a DC electric potential in the range from about 5V to about 30V.

8. The method of claim 1 , wherein one more of the applied electric fields attain a magnitude of at least 2 MV/m within the via.

9. The method of claim 1 , wherein a higher dielectrophoretic force is applied on the second nanoelements than on the first nanoelements.

10. The method of claim 1 , wherein the second nanoelements are used at a higher concentration than the first nanoelements.

11. The method of claim 1 wherein the first and second nanoelements are conducting, and the first and second nanoelements are not the same.

12. The method of claim 1 , wherein the fabricated hybrid nanostructure is a nanoantenna, an optical device, a plasmonic device, or a biosensor.

Assignees

• Univ Northeastern

Inventors

• Busnaina Ahmed
• Yilmaz Cihan
• Kim Taehoon
• Somu Sivasubramanian

Classifications

• H10P14/47

  Electrolytic deposition, i.e. electroplating; Electroless plating · CPC title

• H10W20/0554

  of nanotubes or nanowires · CPC title

• H10W20/063

  by forming conductive members before forming protective insulating material · CPC title

• H10W20/057

  by selectively depositing, e.g. by using selective CVD or plating · CPC title

• B81C1/00111 Primary

  Tips, pillars, i.e. raised structures (microneedles A61M37/0015) · CPC title