Featured Research

from universities, journals, and other organizations

Innovation promises expanded roles for microsensors

Date:
February 7, 2012
Source:
Purdue University
Summary:
Researchers have learned how to improve the performance of sensors that use tiny vibrating microcantilevers to detect chemical and biological agents for applications from national security to food processing.

Researchers have learned how to improve the performance of sensors that use tiny vibrating "microcantilevers," like the one pictured here, to detect chemical and biological agents for applications from national security to food processing.
Credit: Vijay Kumar, Birck Nanotechnology Center, Purdue University

Researchers have learned how to improve the performance of sensors that use tiny vibrating microcantilevers to detect chemical and biological agents for applications from national security to food processing.

The microcantilevers -- slivers of silicon shaped like small diving boards -- vibrate at their natural, or "resonant," frequency. Analyzing the frequency change when a particle lands on the microcantilever reveals the particle's presence and potentially its mass and composition.

The sensors are now used to research fundamental scientific questions. However, recent advances may allow for reliable sensing with portable devices, opening up a range of potential applications, said Jeffrey Rhoads, an assistant professor of mechanical engineering at Purdue University.

Creating smaller sensors has been complicated by the fact that measuring the change in frequency does not work as well when the sensors are reduced in size. The researchers showed how to sidestep this obstacle by measuring amplitude, or how far the diving board moves, instead of frequency.

"When you try to shrink these systems, the old way of measuring does not work as well," Rhoads said. "We've made the signal processing part easier, enabling small-scale, lower-power sensors, which are more reliable and have the potential for higher sensitivities."

Findings are detailed in a paper appearing online this week in the Journal of Microelectromechanical Systems. The paper was written by graduate research assistants Vijay Kumar and J. William Boley, undergraduate student Yushi Yang, mechanical engineering professor George Chiu and Rhoads. An earlier paper was published in April in the weekly journal Applied Physics Letters.

The work is based at the Dynamic Analysis of Micro- and Nanosystems Laboratory at Purdue's Birck Nanotechnology Center.

The aim is to apply the new approach to build sensors capable of reliably measuring particles that have a mass of less than one picogram -- or trillionth of a gram -- at room temperature and atmospheric pressure.

The microcantilever sensors have promise in detecting and measuring constituents such as certain proteins or DNA for biological testing in liquids, gases and the air. The devices might find applications in breath analyzers, industrial and food processing, national security and defense, and food and water quality monitoring.

"One question about these sensors is whether they will continue to work in the field," Rhoads said. "We've been doing a lot of blind, false-positive and false-negative tests to see how they perform in a realistic environment. We've had only a few false positives and negatives in months of testing."

The findings focus on detecting gases and show that the new sensors should be capable of more reliably measuring smaller quantities of gas than is possible with current sensors.

Measuring amplitude is far easier than measuring frequency because the amplitude changes dramatically when a particle lands on the microcantilever, whereas the change in frequency is minute.

"We haven't beaten the sensitivity of all other sensors yet," Rhoads said. "But the difference is that we are trying to do it with a compact device that is truly implementable at the microscale, while many others use fairly large laboratory equipment."

The researchers tested the cantilevers in a chamber filled with precisely controlled quantities of methanol to study their reliability. A patent is pending on the invention.

The research has been partially funded by the National Science Foundation. Student support was provided by Purdue and the Purdue Research Foundation.


Story Source:

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


Journal Reference:

  1. Vijay Kumar, Yushi Yang, J. William Boley, George T.-C. Chiu, Jeffrey F. Rhoads. Modeling, Analysis, and Experimental Validation of a Bifurcation-Based Microsensor. Journal of Microelectromechanical Systems, 2012; DOI: 10.1109/JMEMS.2011.2182502

Cite This Page:

Purdue University. "Innovation promises expanded roles for microsensors." ScienceDaily. ScienceDaily, 7 February 2012. <www.sciencedaily.com/releases/2012/02/120207133752.htm>.
Purdue University. (2012, February 7). Innovation promises expanded roles for microsensors. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2012/02/120207133752.htm
Purdue University. "Innovation promises expanded roles for microsensors." ScienceDaily. www.sciencedaily.com/releases/2012/02/120207133752.htm (accessed September 1, 2014).

Share This




More Matter & Energy News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. Video provided by Reuters
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:
from the past week

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