ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Boston University's Tiny Torsion Oscillator

Updated on November 9, 2008

A research group at Boston University recently published their successful measurement of the torque produced by a nano-scale motor less than a micron in size in Nature Nanotechnology. Although the motor's tiny size is remarkable, even more interesting is the principle on which it operates; direct conversion of a change in an electron's angular momentum into torque.

All electrons possess a fundamental quantum property called "spin" that corresponds to their intrinsic angular momentum. An electron can only have two possible values for its spin: +1/2 or -1/2. The new motor creates torque by passing a current of electrons that all possess the same spin through a junction between a ferromagnetic and nonmagnetic material. When the electrons move from the ferromagnetic material to the nonmagnetic material, they change the sign of their spin. Because this requires the electrons to change their angular momentum, conservation of angular momentum causes torque to be exerted on the junction.

The research group, which was lead by Professor Pritiraj Mohanty, created the motor by using electron beam lithography and surface nanomachining to connect a cobalt wire with a gold wire in the center of a tiny torsion oscillator that measured a mere 12 x 6 micrometers. By sending a current of one microampere through the cobalt-gold junction, they were able to measure the 2.3E-22 Nm of torque produced by the device.

The tiny torsion oscillator on which the cobalt/gold junction was mounted is a significant breakthrough in nano-motor research, as it is roughly an order of magnitude more sensitive than current optical teweezer techniques. The authors speculate that their torsion sensor could be useful for experiments involving measurements of DNA untwisting, torsion-producing molecules, and magnetoelectronics.

The paper containing the research is currently available from Nature online, but requires a subscription.


    0 of 8192 characters used
    Post Comment

    • Alexander Mark profile image

      Alexander Silvius 

      9 years ago from Portland, Oregon

      Fascinating but way beyond my education level. What would the "popular science" applications be? (In terms of ordinary every day appliances and activities). I apologize if I seem small minded, I'm sure that using this nano-motor for research purposes will have far reaching benefits. Still, it's amazing humans can manipulate objects at the electron level to produce power and minute change.


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)