Frank C Gomez

US Patent:

20080163946, Jul 10, 2008

Filed:

Dec 28, 2007

Appl. No.:

11/966958

Inventors:

Frank A. Gomez - Montebello CA, US
Attila Gaspar - Debrecen, HU
Menake E. Piyasena - Silver Spring MD, US

Assignee:

The Trustees of California State University - Los Angeles CA

International Classification:

F16K 15/14
F16K 31/06

US Classification:

137843, 25112901

Abstract:

A simple, external in-line valve for use in microfluidic devices constructed of elastomer such as polydimethylsiloxane (PDMS) is described. The actuation of the valve is based on the principle that flexible polymer walls of a liquid channel can be pressed together by the aid of a permanent magnet and a small metal bar. In the presence of a small NdFeB magnet lying below the channel of interest, the metal bar is pulled downward simultaneously pushing the thin layer of PDMS down thereby closing the channel stopping any flow of fluid. The operation of the valve is dependent on the thickness of the PDMS layer, the height of the channel, the gap between the chip and the magnet and the strength of the magnet. The microfluidic channels are completely closed to fluid flows commonly used in microfluidic applications. The valve allows for fabrication of a “thin chip” that allows for detection of chromophoric species within the microchannel via an external fiber optics detection system. C18-Modified reverse phase silica particles are packed into the microchannel using a temporary taper created by the magnetic valve and separations using both pressure and electrochromatographic driven methods is detailed.

US Patent:

20120118410, May 17, 2012

Filed:

Nov 15, 2011

Appl. No.:

13/297250

Inventors:

Frank A. GOMEZ - Montebello CA, US
Attila Gaspar - Debrecen, HU
Menake E. Piyasena - Silver Spring MD, US

Assignee:

THE TRUSTEES OF CALIFORNIA STATE UNIVERSITY - Los Angeles CA

International Classification:

F15D 1/00

US Classification:

137561 R

Abstract:

An external in-line valve for use in microfluidic devices constructed of elastomer such as polydimethylsiloxane (PDMS) is described. The valve is actuated by a permanent magnet and a metal bar that press together the polymer walls of a channel. The metal bar is pulled downward by a small NdFeB magnet below the channel, simultaneously pushing the thin layer of PDMS down, closing the channel, and stopping flow of fluid. Operation of the valve is dependent on thickness of the PDMS layer, height of the channel, the gap between chip and magnet, and magnet strength. The valve allows for fabrication of a “thin chip” that allows for detection of chromophoric species within the microchannel via an external fiber optics detection system. C18-Modified reverse phase silica particles are packed into the microchannel using a temporary taper created by the magnetic valve. Separations using both pressure and electrochromatographic driven methods are detailed.

US Patent:

20150209690, Jul 30, 2015

Filed:

Feb 4, 2015

Appl. No.:

14/614376

Inventors:

- Pasadena CA, US
Alvaro GOMEZ - Pasadena CA, US
Frank GOMEZ - Montebello CA, US
Axel SCHERER - BARNARD VT, US

International Classification:

B01D 15/22
B29C 65/70
B01L 3/00

Abstract:

A device and method for making a microfluidic separation device. A microfluidic separation device could include a microfluidic column having an inlet, the microfluidic column being configured to hold a first fluid and the microfluidic column including a porous portion, and an outlet attached to the microfluidic column, the outlet being configured to output a second fluid. The method may include providing a microfluidic column having an inlet, configuring the microfluidic column to hold a first fluid, forming a porous portion in the microfluidic column, and attaching an outlet to the microfluidic column.