Clark School Home UMD

ISR News Story

Micro-Knife-Edge Techniques for Sealing of Microfluidic Systems (ISR IP)

ISR intellectual property available to license

Theresa Michele Valentine, Gary Rubloff, Reza Ghodssi, Jung Jin Park

U.S. Patent: 7,375,404

Researchers at the University of Maryland, College Park, have developed an invention that relates to fabrication of leak-tight microfluidic systems for biomedical and other applications. A major technical challenge in microfluidics is to achieve design and fabrication strategies that enable simple or complex networks of fluid channels to be accomplished in a leak-tight fashion. The micro-knife-edge designs have potential to dramatically enhance the robustness and reliability of the fluidic sealing. With rapidly growing interest in microfluidic applications and the apparent absence of robust solutions to this problem, we believe this invention could have major value.

The micro-knife-edge technique allows a microfluidic system (channels, reservoirs and electrodes on a patterned substrate) to be clamped in a leak-tight, water-level "packaging" with fluid inlets and outlets and electrical connections. In conventional approaches, one would seal the fluidic network (except for peripheral fluidic inputs and outputs) either using a permanent bonding on a top layer over the microfluidic channels or using a compressible gasket of some sort. The former has drawbacks in that it cannot be disassembled. The latter has drawbacks in that sealing is not robust, because it is difficult to achieve enough deformation force at all points surrounding the microfluidic channels.

The addition of micro-knife-edges to the wafer design, however, provides localized force on the gasket material close to the fluid flow path and creates a much better seal. A similar "knife-edge" seal is used at a macro-scale in vacuum systems, where a metal gasket is compressed by sharp edges on a flange to seal a vacuum chamber. The scope of the invention is for sealing of microfluidic devices when wafer-level packaging (i.e., allowing a wafer to be dropped into a packaging device immediately after processing with all fluid and electrical connections pre-set) is desired. Because of the small size of the microchannels, nonuniformities and bowing in the packaging can easily lead to leakage. However, the additional force applied to the gasket by the micro-knife-edge allows the channels to seal adequately for fluid flow to occur.

For more information
If you would like to license this intellectual property, have questions, would like to contact the inventors, or need more information, contact ISR External Relations Director Jeff Coriale at or 301.405.6604.

Find more ISR IP
You can go to our main IP search page to search by research category or faculty name. Or view the entire list of available IP on our complete IP listing page.

ISR-IP-Ghodssi ISR-IP-Rubloff ISR-IP-nano ISR-IP-MEMS

Related Articles:
Controlled Electromechanical Deposition of Polysaccaride Film and Hydrogel and Materials Formed Therefrom (ISR IP)
Assembly of Chitosan onto an Electrode Surface (ISR IP)
Programmable Selective Deposition of Biofunctional Polymer Surfaces (ISR IP)
Thermo-Bio-Lithography (ISR IP)
Fabrication and Integration of Polymeric BioMEMS (ISR IP)
A Microcantilever Sensor with Integrated Optical Readout for Liquid Samples (ISR IP)
A Device and Method for Measuring Microcantilever Beam Displacement by Interference Fringe Shifting (ISR IP)
Lateral Two-Terminal Nanotube Devices and Method for their Formation (ISR IP)
EquiPSim: Equipment and Process Simulation Learning Module (ISR IP)
SimPLE: Simulated Processes in a Learning Environment (ISR IP)

June 22, 2007

Prev   Next



For more information, contact ISR External Relations Director
Jeff Coriale at or 301.405.6604.

Current Headlines

Jonathan Simon is invited speaker at Paris Workshop on Decoding of Sound and Brain

Barg, Tamo named winners of IEEE Information Theory Society Paper Awad

Networking reception brings alumni together

Gary Rubloff to receive Senior Faculty Outstanding Research Award

Grad students Winkler, Subramanian rank highly in U21 3MT video contest

ISR participates in NSF 30th Anniversary ERC Celebration

White Symposium to Examine Collective Animal Behavior and Control of Robotic Networks

University of Maryland, College Park & Baltimore Campuses Announce Seed Grant Winners

Naomi Leonard to be inducted into Innovation Hall of Fame

Baras, Yu, Sadler issued patent for wireless communication authentication

News Resources

Return to Newsroom

Search News

Archived News

Events Resources

Events Calendar