Thin-surface liquid crystal based voltage sensor

Patent metadata

Field	Value
Publication number	US-9488891-B2
Application number	US-201414120067-A
Country	US
Kind code	B2
Filing date	Apr 22, 2014
Priority date	Apr 22, 2013
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

A method for fabricating a liquid crystal (LC) device and large area LC devices is provided. The method includes forming a LC layer and forming a coated silicon wafer on at least one surface of the LC layer. The coated silicon wafer includes a sacrificial layer for providing structural strength during fabrication of the LC device and a thin coating layer serving as an external light transmissive layer, and the coated silicon wafer is formed such that the thin coating layer is formed on the LC layer and the sacrificial layer is formed on the thin coating layer. The method also includes fabricating the LC device and selectively removing at least a portion of the sacrificial layer of the coated silicon wafer to expose at least a portion of the thin coating layer to serve as an external layer of the LC device.

First claim

What is claimed is:

1. A method for fabricating a liquid crystal device, the method comprising:
(a) forming a liquid crystal layer;
(b) forming a coated silicon wafer in direct contact with at least one surface of the liquid crystal layer, the coated silicon wafer comprising a sacrificial layer and a thin coating layer;
wherein the sacrificial layer provides structural strength during fabrication of the liquid crystal;
wherein the thin coating layer serves as an external light transmissive layer; and
wherein the coated silicon wafer is formed such that the thin coating layer is formed on the liquid crystal layer and the sacrificial layer is formed on the thin coating layer;

(c) fabricating the liquid crystal device; and
(d) selectively removing at least a portion of the sacrificial layer of the coated silicon wafer to substantially expose at least a portion of the thin coating layer to serve as an external layer of the liquid crystal device to allow light transmission altering samples to be placed in close proximity to the external layer for viewing through the liquid crystal layer.

2. The method for fabrication in accordance with claim 1 wherein the step of forming the liquid crystal layer comprises forming a super twisted nematic liquid crystal layer.

3. The method for fabrication in accordance with claim 1 wherein the step of forming the coated silicon wafer comprises forming the sacrificial layer comprising silicon.

4. The method for fabrication in accordance with claim 1 wherein the step of forming the coated silicon wafer comprises forming the thin coating layer comprising silicon dioxide.

5. The method for fabrication in accordance with claim 1 wherein the step of forming the coated silicon wafer comprises forming the thin coating layer comprising silicon nitride.

6. The method for fabrication in accordance with claim 1 wherein the step of selectively removing at least a portion of the sacrificial layer comprises selectively removing an area of the sacrificial layer of the coated silicon wafer to expose a portion of the thin coating layer to serve as an external layer of the liquid crystal device by immersing the liquid crystal device in potassium hydroxide.

7. The method for fabrication in accordance with claim 1 wherein the step of selectively removing at least a portion of the sacrificial layer comprises selectively removing an area of the sacrificial layer of the coated silicon wafer to expose a portion of the thin coating layer having a thickness less than ten micrometers to serve as an external layer of the liquid crystal device by immersing the liquid crystal device in potassium hydroxide.

8. The method for fabrication in accordance with claim 1 wherein the step of forming the coated silicon wafer in direct contact with at least one surface of the liquid crystal layer comprises forming the coated silicon wafer on only one surface of the liquid crystal layer.

9. The method for fabrication in accordance with claim 1 wherein the step of forming the coated silicon wafer in direct contact with at least one surface of the liquid crystal layer comprises forming the coated silicon wafer on both surfaces of the liquid crystal layer.

10. A method for fabricating a large area liquid crystal device, the method comprising:
(a) forming a large area liquid crystal layer;
(b) forming a coated silicon wafer in direct contact with at least one surface of the large area liquid crystal layer, the coated silicon wafer comprising a sacrificial layer and a thin coating layer;
wherein the sacrificial layer provides structural strength during fabrication of the large area liquid crystal device;
wherein the thin coating layer serves as an external light transmissive layer; and
wherein the coated silicon wafer is formed such that the thin coating layer is formed on the large area liquid crystal layer and the sacrificial layer is formed on the thin coating layer;

(c) fabricating the large area liquid crystal device; and
(d) selectively removing at least a portion of the sacrificial layer of the coated silicon wafer to substantially expose at least a portion of the thin coating layer to serve as an external layer of the liquid crystal device to allow light transmission altering samples to be placed in close proximity to the external layer for viewing through the liquid crystal layer.

11. The method in accordance with claim 10 wherein the step of forming the large area liquid device comprises forming a passive matrix text and/or graphic display.

12. The method in accordance with claim 10 wherein the step of forming the large area liquid crystal device comprises forming an active matrix display.

13. The method in accordance with claim 12 wherein the step of forming the active matrix display comprises forming an active matrix display using transistor thin film (TFT) technology.

14. The method of fabrication in accordance with claim 10 wherein the step of forming the coated silicon wafer in direct contact with at least one surface of the large area liquid crystal layer comprises forming the coated silicon wafer on only one surface of the large area liquid crystal layer.

15. The method for fabrication in accordance with claim 10 wherein the step of forming the coated silicon wafer in direct contact with at least one surface of the large area liquid crystal layer comprises forming the coated silicon wafer on both surfaces of the large area liquid crystal layer.

16. The method for fabrication in accordance with claim 1 wherein the step of selectively removing at least a portion of the sacrificial layer of the coated silicon wafer further comprises selectively removing at least the portion of the sacrificial layer of the coated silicon wafer to completely expose at least the portion of the thin coating layer to serve as the external layer of the liquid crystal device.

17. The method in accordance with claim 10 wherein the step of selectively removing at least a portion of the sacrificial layer of the coated silicon wafer further comprises selectively removing at least the portion of the sacrificial layer of the coated silicon wafer to completely expose at least the portion of the thin coating layer to serve as the external layer of the large area liquid crystal device.

Assignees

• Nat Univ Singapore

Inventors

• Breese Mark Brian Howell

Classifications

• G01R3/00

  Apparatus or processes specially adapted for the manufacture {or maintenance} of measuring instruments {, e.g. of probe tips} · CPC title

• G02F1/1396 Primary

  the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell (G02F1/141 takes precedence) · CPC title

• G01R29/0885

  using optical probes, e.g. electro-optical, luminescent, glow discharge, or optical interferometers · CPC title