Patent US7951300B2 successfully refreshed from Google Patents.
US7951300B2
Active / In Force
US
⏱️ 0.6 years remaining
Water-scale needle array
Assignee: University of Utah Research Foundation Inc
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Filing: 2007-05-29
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Granted: 2011-05-31
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Expires: 2027-05-29
Abstract
Abstract Methods for wafer-scale fabrication of needle arrays can include mechanically modifying a wafer to produce a plurality of vertically-extending columns. The columns are etched to round and reshape the columns into substantially uniformly shaped needles. Needle arrays having needle width non-uniformity of less than about 3% and length non-uniformity of less than about 2% can be produced.
Inventors
- 👤 Rajmohan Bhandari
- 👤 Sandeep Negi
- 👤 Florian Solzbacher
- 👤 Richard A. Normann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 04:02
CPC Classifications
B; B81; B81C; B81C1/00; B81C1/00015; B81C1/00023; B81C1/00111; A; A61; A61M; A61M37/00; A61M37/0015; A61M2037/0053; A61N; A61N1/00; A61N1/02; A61N1/04; A61N1/05; A61N1/0551; B81B; B81B2201/00; B81B2201/05; B81B2201/055; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24479
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
208 words
A method of wafer-scale fabrication of high-aspect ratio needle arrays comprising: providing a mono-crystalline silicon wafer; sawing the wafer on a back side along a first plurality of lines to produce a plurality of mesas; forming glass between the plurality of mesas; sawing the wafer on a front side along a second plurality of lines to a depth sufficient to intersect the glass to produce a plurality of vertically-extending columns, the vertically-extending columns arranged into a plurality of individual arrays of columns separated by sacrificial columns; placing the wafer into a holder so the plurality of vertically-extending columns are exposed and the back side of the wafer is sealed within the holder; immersing the wafer into an etching solution having a mixture of hydrofluoric acid and nitric acid; simultaneously stirring the etching solution in one direction with a stirrer while rotating the wafer in an opposite direction for a first time interval to reshape the vertically-extending columns into rounded columns; positioning the wafer into the etching solution with the vertically-extending columns in an upward position for a second time interval to produce a plurality of substantially uniformly shaped needles from the plurality of rounded columns; and separating the wafer into a plurality of individual needle arrays after etching.
Claim 2
Independent Claim
208 words
A method of wafer-scale fabrication of high-aspect ratio needle arrays comprising: providing a mono-crystalline silicon wafer; sawing the wafer on a back side along a first plurality of lines to produce a plurality of mesas; forming glass between the plurality of mesas; sawing the wafer on a front side along a second plurality of lines to a depth sufficient to intersect the glass to produce a plurality of vertically-extending columns, the vertically-extending columns arranged into a plurality of individual arrays of columns separated by sacrificial columns; placing the wafer into a holder so the plurality of vertically-extending columns are exposed and the back side of the wafer is sealed within the holder; immersing the wafer into an etching solution having a mixture of hydrofluoric acid and nitric acid; simultaneously stirring the etching solution in one direction with a stirrer while rotating the wafer in an opposite direction for a first time interval to reshape the vertically-extending columns into rounded columns; positioning the wafer into the etching solution with the vertically-extending columns in an upward position for a second time interval to produce a plurality of substantially uniformly shaped needles from the plurality of rounded columns; and separating the wafer into a plurality of individual needle arrays after etching.
Claim 3
Dependent Claim
24 words
The method of claim 1 , wherein the first time interval is about 4 minutes and the second time interval is about 8 minutes.
Claim 4
Dependent Claim
29 words
The method of claim 1 , wherein the uniformly shaped needles have a width non-uniformity of less than about 3% and a length non-uniformity of less than about 2%.
Claim 5
Dependent Claim
17 words
The method of claim 1 , further comprising depositing electrically conductive material on the uniformly shaped needles.
Claim 6
Dependent Claim
24 words
The method of claim 1 , further comprising depositing electrically insulative material on the uniformly shaped needles except at tip portions of the needles.
Claim 7
Dependent Claim
20 words
The method of claim 1 , wherein the uniformly shaped needles have a length non-uniformity of less than about 5%.
Claim 8
Dependent Claim
33 words
The method of claim 1 , wherein the plurality of substantially uniformly shaped needles include extra rows of sacrificial needles formed from extra rows of sacrificial columns in the plurality of vertically-extending columns.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2014-05-30 | 2014-11-29 | 2015-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2018-05-30 | 2018-11-29 | 2019-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2022-05-30 | 2022-11-29 | 2023-05-31 | $7700.00 | Window Closed / Lapsed |