Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Microelectronics: Taking the heat off microfluidic chips

25.04.2013
Replacing a high-temperature processing technique with an infrared treatment allows the manufacture of tiny devices without damaging the polymer components
Microfluidic devices are allowing microelectronic engineers to shrink laboratories to the size of a computer chip. By ferrying reagents through a series of microscopic channels and reservoirs carved into a flat plate, researchers can develop new chemical reactions or monitor the cellular effects of drugs on a much smaller scale, potentially saving time and money.

Some of these microfluidic devices even have electrical components that act as heaters or sensors, for example. But researchers have struggled to develop a rapid, low-cost method for creating the detailed metal patterns that make up these circuits.

Conventional techniques tend to require high-temperature processing, which can damage the transparent polymers typically used to build microfluidic devices, such as polycarbonate (PC) or poly(methyl methacrylate) (PMMA). Despite this drawback, the polymers are preferred over more robust alternatives because they “have very good optical properties, which most microfluidic devices require, and they are viable for plastic injection molding, which enables high-volume production,” explains Zhaohong Huang of the A*STAR Singapore Institute of Manufacturing Technology.

Huang and his co-workers developed an alternative process that avoids exposing the polymers to high temperatures, and used it to build complex metal-patterned microfluidic devices (see image)1. They first covered sheets of PC or PMMA with thin layers of chromium, copper and nickel, and added a coating of a light-sensitive material called a photoresist. At this stage, the 'sandwich' would normally be baked at around 100 °C to remove any residual solvents after the coating process. But these temperatures would soften and warp the polymer, potentially cracking or loosening the metal layer.

Instead, Huang’s team used infrared heating elements to eliminate the solvents. The metal layer acted as a protective barrier, reflecting more than 95% of any infrared radiation that hit it, meaning that the radiation warmed the photoresist layer but not the polymer beneath.

The researchers then used standard photolithography processes to create the microfluidic device. They placed a patterned mask over the sandwich and shone ultraviolet light to erode some areas of the photoresist; then, they etched away the exposed areas of metal beneath using a wash of chemicals. Stripping off any remaining photoresist left a clean metal pattern, which had features as small as 10 micrometers in width.

“If the surface finish is gold, our method can cut costs by more than 90%,” says Huang. His team is now refining the process, and creating patterns of different metals with catalytic properties, which could speed up chemical reactions inside microfluidic devices.

The A*STAR-affiliated researchers contributing to this research are from the Singapore Institute of Manufacturing Technology

Journal information

Huang, Z. H., Lim, B. C. & Wang, Z. F. Process development for high precision metal patterning on low glass transition polymer substrates. Microelectronic Engineering 98, 528–531 (2012).

A*STAR Research | Research asia research news
Further information:
http://www.research.a-star.edu.sg/research/6660
http://www.researchsea.com

More articles from Process Engineering:

nachricht Dresdner scientists print tomorrow’s world
08.02.2017 | Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS

nachricht New technology for mass-production of complex molded composite components
23.01.2017 | Evonik Industries AG

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>