Zettl Group Page

Research Highlights 

 

Nanoscale Reversible Mass Transport for Archival Memory

Gavi Begtrup, Will Gannett, Tom Yuzvinsky, Alex Zettl
Department of Physics, University of California at Berkeley
Center of Integrated Nanomechanical Systems, University of California at Berkeley
Materials Sciences Division, Lawrence Berkeley National Laboratory
Berkeley, CA 94720, U.S.A.

 

Vin Crespi

Pennsylvania State University

University Park, Pennsylvania, 16802

The following media files are intended for public access, and may be reproduced with credit: "Courtesy Zettl Research Group, Lawrence Berkeley National Laboratory and University of California at Berkeley." All rights reserved ©2009.

Introduction

Digital storage devices have become ubiquitous in our lives; music, photographs, and even the written word have moved from their traditional analog formats to newer digital ones.  However, this move to digital storage has raised concerns about the lifetime of storage media.  While ancient analog archival media (e.g. stone and vellum) can preserve their data for thousands of years, digital storage technologies such as optical discs, magnetic discs, and magnetic tape are thought to last at most a century (and in many cases much less).   Obviously stone and vellum are not well-suited to today’s volume of data: the pits in a CD are spaced about a micron apart, carvings in stone have feature sizes closer to a centimeter.  New archival technologies will have to combine the best features of both, storing data at a high density with long lifetimes.

We have developed a new mechanism for digital memory storage with the potential to store data with both long lifetime and high density.  Our memory device consists of a crystalline iron nanoparticle enclosed in a multiwalled carbon nanotube.  The nanotube can be reversibly moved through the nanotube by applying a low voltage, "writing" the device to a binary state represented by the position of the nanoparticle.  The state of the device can then be subsequently read by a simple resistance measurement.

Refer also to the article by Lynn Yarris for LBL, found here.

Artwork

If you use any of the following images, please include the credit "Courtesy Zettl Research Group, Lawrence Berkeley National Laboratory and University of California at Berkeley."

Egyptian hieroglyphs, a low-density, long-lifetime storage medium.  Courtesy Rusty Orr.

Hieroglyphs (JPEG 329 KB)

Images

If you use any of the following images, please include the credit "Courtesy Zettl Research Group, Lawrence Berkeley National Laboratory and University of California at Berkeley."

Schematic of an array of carbon nanotube memory devices.  In this image, the memory devices are displaying a binary sequence "1 0 1 1 0".

Nanotube memory array (JPEG 67 KB)
Nanotube memory array (high res) (JPEG 133 KB)
Nanotube memory array (vector) (EPS 718 KB)

The reversibility of the nanoparticle motion allows a memory "bit" that can be rewritten.  Here we show this property, moving the nanoparticle back and forth over the position threshold defining the state of the device.

Nanotube memory state (JPEG 17 KB)
Nanotube memory state (high res) (JPEG 131 KB)

A plot showing typical data storage lifetimes vs bit density for a variety of media.  Note that the memory device demonstrated here appears in the upper right of the plot, well above the other materials shown.

Plot of bit density vs lifetime, black background (JPEG 215 KB)
Plot of bit density vs lifetime, white background (JPEG 515 KB)
Plot of bit density vs lifetime, white background (vector) (EPS 67 KB)

Video

If you use any of the following images, please include the credit "Courtesy Zettl Research Group, Lawrence Berkeley National Laboratory and University of California at Berkeley."

A video of our nanotube memory device as the iron is moved back and forth.

Memory device video (MOV 6.5 MB)

A schematic video of an iron nanoparticle shuttle moving through a carbon nanotube.  Courtesy Vin Crespi.

Shuttle video (MOV 988 KB)

Acknowledgements

This work was supported by the Director, Office of Energy Research, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the US Department of Energy under Contract DE-AC02-05CH11231. T.Y. acknowledges support from the National Science Foundation within the Center of Integrated Nanomechanical Systems, and W.G. acknowledges support from an IGERT Grant from the National Science Foundation. V.C. acknowledges support from the National Science Foundation.


 
Last modified: June 9, 2009.