Featured Research

from universities, journals, and other organizations

New Microprinting Technique Improves Nanoscale Fabrication

Date:
August 31, 2005
Source:
Penn State
Summary:
Scientists will announce next month a new technique called microdisplacement printing, which makes possible the highly precise placement of molecules during the fabrication of nanoscale components for electronic and sensing devices. The new technique, which also extends the library of molecules that can be used for patterning, will be described in the 14 September issue of the journal Nano Letters.

A demonstration of microdisplacement printing, in which a weakly bound film is displaced by contact stamping with molecules that bind more strongly to the substrate. This process leaves a patterned film with regions of strongly bound molecules (where the weakly bound molecules were displaced) and regions of the remaining weakly bound molecules.
Credit: Image courtesy of Penn State

Scientists will announce next month a new technique calledmicrodisplacement printing, which makes possible the highly preciseplacement of molecules during the fabrication of nanoscale componentsfor electronic and sensing devices. The new technique, which alsoextends the library of molecules that can be used for patterning, willbe described in the 14 September issue of the journal Nano Letters by ateam led by Paul S. Weiss, professor of chemistry and physics at PennState.

Related Articles


The new microdisplacement technique is based on a widelyused patterning method known as microcontact printing--a simple way offabricating chemical patterns that does not require clean rooms andother kinds of special and expensive environments. Both methods involve"inking" a patterned rubber-like stamp with a solution of molecules,then applying the inked stamp to a surface.

"Microdisplacementgives us more control over the precision with which the patterns areplaced and retained, and also allows us to use a wider range ofmolecules," Weiss says.

One of the limitations of microcontactprinting is that its precision is limited at the edges of a stampedpattern by the tendency of the applied molecules to skitter across thestamped surface, blurring or obliterating the applied pattern anddestroying its usefulness. Weiss's improved microdisplacement techniquesolves this problem by applying a self-assembled-monolayer film--asingle ordered layer of spherical adamantanethiolate molecules--to keepthe stamped molecules in place on the surface. "We specificallyengineered the adamantanethiol molecule to have a very weak chemicalbond with the surface so that it would detach easily when bumped by astronger-bonding molecule," Weiss explains. The molecules inked on thestamp replace the adamantanethiolate molecules wherever they touch themonolayer film, but the surrounding molecules in the film remainattached to the surface to prevent the applied molecules from wandering.

"Microdisplacementprinting uses many of the same procedures as microcontact printingexcept one first prepares the substrate by coating it with aself-assembled monolayer of adamantanethiolate, which is inexpensiveand easy to apply," Weiss explains. "You dip the substrate in asolution of these molecules, pull it out, and they assemble themselvesinto an ordered film one molecule thick."

In addition toproviding more control over the precision of stamped patterns, the newmicrodisplacement technique also relaxes the requirements in preciselypositioning a series of stamps used to apply consecutive patterns withdifferent molecular inks. "You don't have to be extremely precise aboutthe exact placement of the stamps as long as you apply the molecularinks in order of their bonding strengths," Weiss explains. Eachsuccessive layer of molecules either will displace or will not displacethe already-applied molecules, depending on their relative bondingstrengths with the underlying surface.

The research was aided bythe Weiss lab's unusual collection of microscopes, which enable thescientists to get a clear picture of the results of their experiments,both at the broad scale of a stamped pattern and at the narrow scale ofjust a single molecule. One scanning tunneling microscope that Weissand his group designed and built themselves, for example, has 1,000times more resolution than is needed to image an individual atom.

Adamantanethiolis related to the family of alkanethiol molecules, which have beenstudied extensively as a model systems for their ability to formwell-ordered monolayer films on gold. Weiss and his team were studyingthe adamantanethiolate-on-gold system when graduate student ArrelaineDameron discovered that stronger-bonding molecules easily displaced theadamantanethiolate molecules. Her discovery has led to further studiesof this system by the Weiss team, including how the displacement can beapplied in a broad range of applications using a variety of materials.

"Wehave mapped out strategies in this model system and are nowinvestigating how we can apply these strategies more broadly as thechemistry is developed for self-assembled monolayers on othersubstrates, especially semiconductors," Weiss says. "Our goals are tosee how far we can take these kinds of simple techniques, along withour knowledge of intermolecular interactions, to bridge the1-to-100-nanometer length scale in nanofabrication, which even at thehigh end currently requires very difficult, slow, and expensivetechniques."

In addition to Weiss and Dameron, the Penn Stateresearch team includes postdoctoral fellows Jennifer Hampton and SusanGillmor and graduate students Rachel Smith and T. J. Mullen. Theresearch was supported by the Air Force Office of Scientific Research,the Army Research Office, the Defense Advanced Research ProjectsAgency, the National Science Foundation, the Office of Naval Research,and the Semiconductor Research Corporation. The work was performed as apart of both the Center for Nanoscale Science and the NationalNanofabrication Infrastructure Network.


Story Source:

The above story is based on materials provided by Penn State. Note: Materials may be edited for content and length.


Cite This Page:

Penn State. "New Microprinting Technique Improves Nanoscale Fabrication." ScienceDaily. ScienceDaily, 31 August 2005. <www.sciencedaily.com/releases/2005/08/050819124323.htm>.
Penn State. (2005, August 31). New Microprinting Technique Improves Nanoscale Fabrication. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2005/08/050819124323.htm
Penn State. "New Microprinting Technique Improves Nanoscale Fabrication." ScienceDaily. www.sciencedaily.com/releases/2005/08/050819124323.htm (accessed October 25, 2014).

Share This



More Matter & Energy News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
Real-Life Transformer Robot Walks, Then Folds Into a Car

Real-Life Transformer Robot Walks, Then Folds Into a Car

Buzz60 (Oct. 24, 2014) Brave Robotics and Asratec teamed with original Transformers toy company Tomy to create a functional 5-foot-tall humanoid robot that can march and fold itself into a 3-foot-long sports car. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Police Testing New Gunfire Tracking Technology

Police Testing New Gunfire Tracking Technology

AP (Oct. 24, 2014) A California-based startup has designed new law enforcement technology that aims to automatically alert dispatch when an officer's gun is unholstered and fired. Two law enforcement agencies are currently testing the technology. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins