Featured Research

from universities, journals, and other organizations

Extraordinary sensors pushed to their boundaries: New step is being taken in development of ultra-stable sensors of small forces

Date:
January 9, 2014
Source:
Ecole Polytechnique Fédérale de Lausanne
Summary:
A new step is being taken in the development of ultra-stable sensors of small forces. EPFL researchers have found a way to eradicate external perturbations from interfering with their state-of-the art optomechanical measurement systems.

A new step is being taken in the development of ultra-stable sensors of small forces. EPFL researchers have found a way to eradicate external perturbations from interfering with their state-of-the art optomechanical measurement systems.
Credit: Image courtesy of Ecole Polytechnique Fédérale de Lausanne

Last year, Tobias Kippenberg and his team from the Laboratory of Photonics and Quantum Measurements (LPQM1) presented a new-generation sensor capable of detecting very small forces with unprecedented efficiency. These devices, developed and fabricated at the Center of MicroNanofabrication (CMi) at EPFL have already opened new frontiers in both applied and fundamental science.

Related Articles


However the potential of these systems, called nanomechanical oscillators, is affected by their increased sensitivity to external perturbations. So far some "noises," due to temperature variations for instance, have prevented the device from working perfectly. These imperfections might now soon disappear.

EPFL scientists Emanuel Gavartin, Pierre Verlot and Tobias Kippenberg have recently managed to isolate and eliminate external "noises" that deteriorate the performance of the sensors. Their discovery paves the way to the development of some of the best sensors in the world. Their results have been published in Nature Communications.

A microscopic vibrating string

This is how it works: nanomechanical oscillators are composed of a string a few hundred nanometers thick, that can be actuated by applying a known external force. Such a device can then be used to detect very small particles, e.g. single molecules, which arrive on its surface. Depending on its property, each molecule changes the string vibration in a specific way. These changes act as a molecule's "signature," allowing researchers to know what kind of molecule is present in a specific area, even in a very small quantity.

A laser to read the vibrations

In order to read the changes in the string vibration, the scientists normally direct a laser into a round glass cavity located under the string. The laser beam spins several ten thousand times around the disk for a few nanoseconds, and finally gets out. During the spin, the beam undergoes changes depending on the string's vibration. By analyzing the frequency changes in the laser before and after the spin, researchers can therefore find out everything that happened at the string surface.

The problem now is that this extraordinary sensors are not only sensitive towards signals or forces one seeks to detect, but also towards external noise sources resulting from different phenomena such as temperature variations in a room, or chemical processes occurring at the device's surface.

Two types of noises

In reality, nanomechanical oscillators suffer from two kinds of perturbation. First of all, the device is subject to a natural imprecision governed by fundamental physics that affects all oscillators. The second kind of perturbations is caused by external changes in the environment. "Until now the internal perturbations had never affected the measurement in a significant way," Emanuel Gavartin comments. "We were more concerned about the noises coming from the surroundings of the oscillator, as they have a much larger impact on the oscillator system."

An oscillation in several directions

To get rid of the external frequency fluctuations, the scientists relied on a simple fact. When it vibrates like the string of a guitar, the microscopic string simultaneously oscillates up and down and left and right, as well as in several other directions. Just like an oscillating guitar string with several overtones.

EPFL scientists observed that when external noises perturb the device -- a rise of temperature, for instance -- there was a correlation between the changes occurring in the up and down mode, and in the left and right mode. In other words, they found out that each oscillation mode responded similarly to an identical external perturbation.

Given this phenomenon, they used one mode to detect the external noise perturbation and then derived a correction to remove the external noise from the other mode to be used for sensing applications. The results were really convincing, as they allowed a nearly total removal of external noise. "When such a perturbation occurs, we proceed very quickly to the analysis of the variations of the oscillation mode," explains Emanuel Gavartin. "Then, we apply a laser to counteract the fluctuation and stabilize the device."

A very efficient stabilization

The new method will allow developing almost perfect ultra-efficient sensors, with an impact in both fundamental and applied studies. Thanks to the presence of different modes, the noise correction does not affect the detection capabilities of the 'sensing mode'. "Our technique is very promising for the detection of very small masses. Further applications lie in fundamental science, as low-noise mechanical oscillators pave the way to state-of-the-art experiments in quantum physics," says Emanuel Gavartin.


Story Source:

The above story is based on materials provided by Ecole Polytechnique Fédérale de Lausanne. Note: Materials may be edited for content and length.


Journal Reference:

  1. Emanuel Gavartin, Pierre Verlot, Tobias J. Kippenberg. Stabilization of a linear nanomechanical oscillator to its thermodynamic limit. Nature Communications, 2013; 4 DOI: 10.1038/ncomms3860

Cite This Page:

Ecole Polytechnique Fédérale de Lausanne. "Extraordinary sensors pushed to their boundaries: New step is being taken in development of ultra-stable sensors of small forces." ScienceDaily. ScienceDaily, 9 January 2014. <www.sciencedaily.com/releases/2014/01/140109132648.htm>.
Ecole Polytechnique Fédérale de Lausanne. (2014, January 9). Extraordinary sensors pushed to their boundaries: New step is being taken in development of ultra-stable sensors of small forces. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2014/01/140109132648.htm
Ecole Polytechnique Fédérale de Lausanne. "Extraordinary sensors pushed to their boundaries: New step is being taken in development of ultra-stable sensors of small forces." ScienceDaily. www.sciencedaily.com/releases/2014/01/140109132648.htm (accessed October 23, 2014).

Share This



More Matter & Energy News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

3D Printed Instruments Make Sweet Music in Sweden

3D Printed Instruments Make Sweet Music in Sweden

Reuters - Innovations Video Online (Oct. 23, 2014) — Students from Lund University's Malmo Academy of Music are believed to be the world's first band to all use 3D printed instruments. The guitar, bass guitar, keyboard and drums were built by Olaf Diegel, professor of product development, who says 3D printing allows musicians to design an instrument to their exact specifications. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Chameleon Camouflage to Give Tanks Cloaking Capabilities

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Reuters - Innovations Video Online (Oct. 22, 2014) — Inspired by the way a chameleon changes its colour to disguise itself; scientists in Poland want to replace traditional camouflage paint with thousands of electrochromic plates that will continuously change colour to blend with its surroundings. The first PL-01 concept tank prototype will be tested within a few years, with scientists predicting that a similar technology could even be woven into the fabric of a soldiers' clothing making them virtually invisible to the naked eye. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Jet Sales Lift Boeing Profit 18 Pct.

Jet Sales Lift Boeing Profit 18 Pct.

Reuters - Business Video Online (Oct. 22, 2014) — Strong jet demand has pushed Boeing to raise its profit forecast for the third time, but analysts were disappointed by its small cash flow. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Internet of Things Aims to Smarten Your Life

Internet of Things Aims to Smarten Your Life

AP (Oct. 22, 2014) — As more and more Bluetooth-enabled devices are reaching consumers, developers are busy connecting them together as part of the Internet of Things. (Oct. 22) 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