Tip to surface spacing for optimum dispensing controlled by a detected pressure change in the tip
US5143849A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 1991 |
| Grant date | Sep 1, 1992 |
| Priority date | — |
| Expiry date | Mar 21, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/2575
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for automatically adjusting a dispensing tip from a surface onto which liquid is to be dispensed, a proper distance that precludes the dispensing stream from puddling up, or from breaking apart. The method features the formation on the tip of a meniscus of a nominal small volume and advancing the tip and meniscus until the surface is contacted. The resulting decrease in pressure in the tip is measured, to trigger the tip to stop its advance and to start dispensing. In circumstances wherein the contacted surface is hydrophobic so as to ideally require a meniscus depth greater than the nominal depth, the tip is retreated from the surface, during dispensing, to the ideal depth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.