UNSW Australia chemists have invented a new type of tiny lab-on-a-chip device that could have a diverse range of applications, including to detect toxic gases, fabricate integrated circuits and screen biological molecules.
The novel technique developed by the UNSW team involves printing a pattern of miniscule droplets of a special solvent onto a gold-coated or glass surface.
UNSW chemists printed the university's name using a novel technique they developed which involves fabricating a a pattern of ionic liquid droplets onto a gold-coated chip.
"We use a class of 'green' solvents called ionic liquids, which are salts that are liquid at room temperature. They are non-volatile, so this overcomes one of the main problems in making useful miniaturised devices - rapid evaporation of the solvents on the chip," says Dr Chuan Zhao, senior author of the study.
"The versatility of our chips means they could have a wide range of prospective functions, such as for use in fast and accurate hand-held sensors for environmental monitoring, medical diagnosis and process control in manufacturing."
The research is published in the journal Nature Communications. It was carried out by Dr Zhao, Christian Gunawan and Mengchen Ge from the UNSW School of Chemistry.
Lab-on-a- chip devices, where chemical reactions are carried out on a miniature scale, are under intensive development because they offer the promise of faster reaction times, reduced use of materials and high yields of product. Evaporation of solvents on the chip, however, is a big problem because this can affect the concentration of substances and disrupt the reactions. Attempted solutions include containing the solvents within tiny channels or "walls", and having reservoirs to store extra solvent on the chip.
The "wall-less" design developed by the UNSW team - using non-volatile ionic liquids as solvents to fabricate a microarray of droplets chemically anchored to the chip - has several significant advantages.
"Ionic liquids are designer solvents and have wide application. We can now carry out many reactions or analytical procedures in ionic liquids at the micro-scale on a chip with enhanced yields and efficiency," says Dr Zhao.
"These microarray chips can be easily produced in high numbers and are very stable. They can survive being turned upside down and heated to 50 degrees and some can even survive being immersed in another liquid. These properties will be important for commercial applications, including storage and transportation of microchips."
The droplets of ionic liquid are about 50 micrometres across (about half the width of a human hair) and 10 micrometres high.
The UNSW researchers demonstrated several potential uses of the microarrays.
They showed the tiny droplets can act as rapid, sensitive monitors of the presence of a gas, due to their small volume.
They also demonstrated that metal salts dissolved in the droplets could be electrically deposited as microstructures, a technique which could be of use in fabrication of integrated circuits.
Some biological molecules added to the droplets also remained stable and active, opening up the possibility of using the microarrays for diagnostic purposes.
Dr Chuan Zhao: +61 (2) 9385 4645, email@example.com
UNSW Science media: Deborah Smith, +61 (2) 9385 7307, +61 (0) 478 492 060, firstname.lastname@example.org
Deborah Smith | Eurek Alert!
Why do animals fight members of other species?
24.04.2015 | University of California - Los Angeles
Is a small artificially composed virus fragment the key to a Chikungunya vaccine?
24.04.2015 | Paul-Ehrlich-Institut - Bundesinstitut für Impfstoffe und biomedizinische Arzneimittel
KAIST researchers published an article on the development of a novel technique to precisely track the 3-D positions of optically-trapped particles having complicated geometry in high speed in the April 2015 issue of Optica.
Daejeon, Republic of Korea, April 23, 2015--Optical tweezers have been used as an invaluable tool for exerting micro-scale force on microscopic particles and...
A very small and rare species of shark is swimming its way through scientific literature. But don't worry, the chances of this inches-long vertebrate biting...
Ever since computers have been small enough to be fixtures on desks and laps, their central processing has functioned something like an atomic Etch A Sketch, with electromagnetic fields pushing data bits into place to encode data.
Unfortunately, the same drawbacks and perils of the mechanical sketch board have been just as pervasive in computing: making a change often requires starting...
How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was discovered, more or less by coincidence, that cosmic rays provide suitable probes to measure electric fields within thunderclouds. This surprising finding is published in Physical Review Letters on April 24th. The measurements were performed with the LOFAR radio telescope located in the Netherlands.
How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was...
Max Planck researcher Buhalqem Mamtimin determines how much nitrogen oxide is released into the atmosphere from agriculturally used oases.
In order to make statements about current and future air pollution, scientists use models which simulate the Earth’s atmosphere. A lot of information such as...
23.04.2015 | Event News
23.04.2015 | Event News
13.04.2015 | Event News
24.04.2015 | Materials Sciences
24.04.2015 | Materials Sciences
24.04.2015 | Health and Medicine