Christopher M Hahn
Engineers at Fulton Ave, Decatur, IL

License number
Colorado 46824
Issued Date
Sep 13, 2012
Renew Date
Nov 1, 2015
Expiration Date
Oct 31, 2017
Type
Professional Engineer
Address
Address
3848 E Fulton Ave, Decatur, IL 62521
LicenseFiles verified this license of Dec 9, 2016 at the Colorado - Department of Regulatory Agencies.

Professional information

Christopher Hahn Photo 1

Controlling Microdrop Dispensing Apparatus

US Patent:
2004018, Sep 23, 2004
Filed:
Dec 23, 2003
Appl. No.:
10/746039
Inventors:
Ronald Zweifel - Naperville IL, US
Christopher Hahn - Decatur IL, US
International Classification:
G01N035/00
US Classification:
436/043000, 422/100000
Abstract:
A method and apparatus for preventing or limiting damage to capillaries used to dispense microdrops measures the voltage produced by a piezoelectric transducer when the capillary contacts a solid surface or the phase shift occurring when the piezoelectric transducer is operated at its resonant frequency. After distinguishing the voltage created from such contact from the voltage produced from unrelated random sources, corrective action is taken, in one aspect by stopping the relative movement of the capillary and the surface being contacted. The method and apparatus may also be employed to determine the position of a solid or liquid surface. In one embodiment, the method and apparatus of the invention is used to detect contact of the capillary with very small liquid droplets.

Engineers licenses in Colorado