Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Major step towards extremely sensitive chemical sensors

Atomic force microscopy image of island growth in between two electrodes (left and right) of the SAMFET. The self-assembled monolayer islands, in the middle of the figure, conduct charges. In this case, no path is formed between the two electrodes and therefore current cannot flow. The height of the molecules is 3 nanometers; the length of the gap between the electrodes (i.e. the transistor channel length) is 5 microns.
Atomic force microscopy image of island growth in between two electrodes (left and right) of the SAMFET. The self-assembled monolayer islands, in the middle of the figure, conduct charges. In this case, no path is formed between the two electrodes and therefore current cannot flow. The height of the molecules is 3 nanometers; the length of the gap between the electrodes (i.e. the transistor channel length) is 5 microns.

Abstract:
Together with colleagues from the Netherlands, Russia and Austria, researchers of TU/e gained a better understanding of the mechanism behind charge transport in SAMFETs. This opens the door to extremely sensitive chemical sensors, that could be produced in a cost-effective way. The findings were published online in Nature Nanotechnology.

Major step towards extremely sensitive chemical sensors

Eindhoven | Posted on August 14th, 2009

The research was done at Philips Research Eindhoven and Eindhoven University of Technology.

SAMFETs
The SAMFET is a recent example of the development of ‘plastic micro-electronics'- i.e. electronics based on organic materials. Last year, Philips Research managed to build such a transistor by immersing a silicon substrate into solution containing liquid crystalline molecules that self-assemble onto this substrate, resulting in a semi-conductive layer of just a single molecule thick. The monolayer of the SAMFET consists of molecules that are standing upright. Conduction takes place by charges jumping from one molecule to the other.

However, in previous attempts to make a SAMFET, it was observed that as the length of the SAMFET increased, its level of conductivity counterintuitively decreased exponentially. In a joint project Philips Research, the Eindhoven University of Technology (TU/e), the University of Groningen, the Holst Centre, the Enikolopov Institute for Synthetical Polymer Materials in Moscow and the Technical University in Graz, Austria discovered that this decrease is determined by the monolayer coverage, which could be explained with a widely applicable two-dimensional percolation model.

The ultimate chemical sensor
One could compare this to crossing a river by jumping from rock to rock. The closer the rocks are to each other, the quicker one can jump or even walk to the other river bank. So if the monolayer displays more voids, the conductivity decreases dramatically. Up till now, this behavior was an uncharted area and inhibited the use of SAMFETs in applications such as sensors and plastic electronics. The SAMFET's extreme sensitivity could open doors to the development of the ultimate chemical sensor, the research team points out. "If we go back to that river again, another benefit of a SAMFET becomes clear", Martijn Kemerink, assistant professor at the TU/e indicates. "Imagine that there are just enough rocks to cross that river. When you remove just one rock, the effect is significant, for it is impossible to make it to the other side of the river. The SAMFET could be used to make sensors that give a large signal that is triggered by a small change", he continues.

Future steps
At present, SAMFETs are not widely used, for there are alternatives of which the production process is well-established. However, the production process of SAMFETs is extremely simple and material efficient. The transistor requires only a single layer of molecules that is applied by simple immersion into a chemical solution. The same solution can be used for many substrates, for the substrate only takes the necessary (small) amount of molecules. This makes future large-scale production of monolayer electronics efficient, simple and cost-effective.

Publication
The publication "Monolayer coverage and channel length set the mobility in self-assembled monolayer field-effect transistors", by Matthijssen et al. can be found at www.nature.com/nnano/journal/vaop/ncurrent/abs/nnano.2009.201.html.

The research was conducted at Philips Research Eindhoven and Eindhoven University of Technology. It was funded by STW, ONE-P, the Austrian Nanoinitiative en H.C. Starck GMBH.

####

About Eindhoven University of Technology
Eindhoven University of Technology (TU/e) intends to be a research driven, design oriented university of technology at an international level, with the primary objective of providing young people with an academic education within the ‘engineering science & technology’ domain.

For more information, please click here

Contacts:
Den Dolech 2
P.O Box 513, 5600 MB Eindhoven
tel: 31(0)40-247 9111
fax: 31(0)40-245 6087

Copyright © Eindhoven University of Technology

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

FEI Launches Helios G4 DualBeam Series for Materials Science: The Helios G4 DualBeam Series features new capabilities to enable scientists and engineers to answer the most demanding and challenging scientific questions June 27th, 2016

Superheroes are real: Ultrasensitive nonlinear metamaterials for data transfer June 25th, 2016

Russian physicists create a high-precision 'quantum ruler': Physicists have devised a method for creating a special quantum entangled state June 25th, 2016

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Possible Futures

Superheroes are real: Ultrasensitive nonlinear metamaterials for data transfer June 25th, 2016

Russian physicists create a high-precision 'quantum ruler': Physicists have devised a method for creating a special quantum entangled state June 25th, 2016

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Nanotechnology and math deliver two-in-one punch for cancer therapy resistance June 24th, 2016

Self Assembly

Self-assembling icosahedral protein designed: Self-assembling icosahedral protein designed June 22nd, 2016

DNA shaping up to be ideal framework for rationally designed nanostructures: Shaped DNA frames that precisely link nanoparticles into different structures offer a platform for designing functional nanomaterials June 14th, 2016

Automating DNA origami opens door to many new uses: Like 3-D printing did for larger objects, method makes it easy to build nanoparticles out of DNA May 30th, 2016

Searching for a nanotech self-organizing principle May 1st, 2016

Sensors

Researchers discover new chemical sensing technique: Technique allows sharper detail -- and more information -- with near infrared light June 24th, 2016

Artificial synapse rivals biological ones in energy consumption June 21st, 2016

A new form of hybrid photodetectors with quantum dots and graphene June 19th, 2016

Drum beats from a one atom thick graphite membrane June 15th, 2016

Nanoelectronics

Soft decoupling of organic molecules on metal June 23rd, 2016

Tailored DNA shifts electrons into the 'fast lane': DNA nanowire improved by altering sequences June 22nd, 2016

Scientists engineer tunable DNA for electronics applications June 21st, 2016

Novel energy inside a microcircuit chip: VTT developed an efficient nanomaterial-based integrated energy June 10th, 2016

Announcements

FEI Launches Helios G4 DualBeam Series for Materials Science: The Helios G4 DualBeam Series features new capabilities to enable scientists and engineers to answer the most demanding and challenging scientific questions June 27th, 2016

Superheroes are real: Ultrasensitive nonlinear metamaterials for data transfer June 25th, 2016

Russian physicists create a high-precision 'quantum ruler': Physicists have devised a method for creating a special quantum entangled state June 25th, 2016

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Alliances/Trade associations/Partnerships/Distributorships

FEI and University of Liverpool Announce QEMSCAN Research Initiative: University of Liverpool will utilize FEI’s QEMSCAN technology to gain a better insight into oil and gas reserves & potentially change the approach to evaluating them June 22nd, 2016

French Research Team Helps Extend MRI Detection of Diseases & Lower Health-Care Costs: CEA, INSERM and G2ELab Brings Grenoble Region’s Expertise In Advanced Medicine & Magnetism Applications to H2020 IDentIFY Project June 21st, 2016

Research showing why hierarchy exists will aid the development of artificial intelligence June 13th, 2016

UK NANOSAFETY GROUP publishes 2nd Edition of guidance to support safe working with nanomaterials May 30th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic