Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > New imaging device that is flexible, flat, and transparent: Fluorescent light traveling through polymer sheet may lead to user interface devices that respond to gestures alone

This shows the world's first flexible and completely transparent image sensor. The plastic film is coated with fluorescent particles.

Credit: Credit: Optics Express.
This shows the world's first flexible and completely transparent image sensor. The plastic film is coated with fluorescent particles.

Credit: Credit: Optics Express.

Abstract:
Digital cameras, medical scanners, and other imaging technologies have advanced considerably during the past decade. Continuing this pace of innovation, an Austrian research team has developed an entirely new way of capturing images based on a flat, flexible, transparent, and potentially disposable polymer sheet. The team describes their new device and its possible applications in a paper published today in the Optical Society's (OSA) open-access journal Optics Express.

New imaging device that is flexible, flat, and transparent: Fluorescent light traveling through polymer sheet may lead to user interface devices that respond to gestures alone

Washington, DC | Posted on February 20th, 2013

The new imager, which resembles a flexible plastic film, uses fluorescent particles to capture incoming light and channel a portion of it to an array of sensors framing the sheet. With no electronics or internal components, the imager's elegant design makes it ideal for a new breed of imaging technologies, including user interface devices that can respond not to a touch, but merely to a simple gesture.

"To our knowledge, we are the first to present an image sensor that is fully transparent - no integrated microstructures, such as circuits - and is flexible and scalable at the same time," says Oliver Bimber of the Johannes Kepler University Linz in Austria, co-author of the Optics Express paper.

The sensor is based on a polymer film known as a luminescent concentrator (LC), which is suffused with tiny fluorescent particles that absorb a very specific wavelength (blue light for example) and then reemit it at a longer wavelength (green light for example). Some of the reemitted fluorescent light is scattered out of the imager, but a portion of it travels throughout the interior of the film to the outer edges, where arrays of optical sensors (similar to 1-D pinhole cameras) capture the light. A computer then combines the signals to create a gray-scale image. "With fluorescence, a portion of the light that is reemitted actually stays inside the film," says Bimber. "This is the basic principle of our sensor."

For the luminescent concentrator to work as an imager, Bimber and his colleagues had to determine precisely where light was falling across the entire surface of the film. This was the major technical challenge because the polymer sheet cannot be divided into individual pixels like the CCD camera inside a smartphone. Instead, fluorescent light from all points across its surface travels to all the edge sensors. Calculating where each bit of light entered the imager would be like determining where along a subway line a passenger got on after the train reached its final destination and all the passengers exited at once.

The solution came from the phenomenon of light attenuation, or dimming, as it travels through the polymer. The longer it travels, the dimmer it becomes. So by measuring the relative brightness of light reaching the sensor array, it was possible to calculate where the light entered the film. This same principle has already been employed in an input device that tracks the location of a single laser point on a screen.

The researchers were able to scale up this basic principle by measuring how much light arrives from every direction at each position on the image sensor at the film's edge. They could then reconstruct the image by using a technique similar to X-ray computed tomography, more commonly known as a CT scan.

"In CT technology, it's impossible to reconstruct an image from a single measurement of X-ray attenuation along one scanning direction alone," says Bimber. "With a multiple of these measurements taken at different positions and directions, however, this becomes possible. Our system works in the same way, but where CT uses X-rays, our technique uses visible light."

Currently, the resolution from this image sensor is low (32x32 pixels with the first prototypes). The main reason for this is the limited signal-to-noise ratio of the low-cost photodiodes being used. The researchers are planning better prototypes that cool the photodiodes to achieve a higher signal-to-noise ratio.

By applying advanced sampling techniques, the researchers can already enhance the resolution by reconstructing multiple images at different positions on the film. These positions differ by less than a single pixel (as determined by the final image, not the polymer itself). By having multiple of these slightly different images reconstructed, it's possible to create a higher resolution image. "This does not require better photodiodes," notes Bimber, "and does not make the sensor significantly slower. The more images we combine, the higher the final resolution is, up to a certain limit."

The main application the researchers envision for this new technology is in touch-free, transparent user interfaces that could seamlessly overlay a television or other display technology. This would give computer operators or video-game players full gesture control without the need for cameras or other external motion-tracking devices. The polymer sheet could also be wrapped around objects to provide them with sensor capabilities. Since the material is transparent, it's also possible to use multiple layers that each fluoresce at different wavelengths to capture color images.

The researchers also are considering attaching their new sensor in front of a regular, high-resolution CCD sensor. This would allow recording of two images at the same time at two different exposures. "Combining both would give us a high-resolution image with less overexposed or underexposed regions if scenes with a high dynamic range or contrast are captured," Bimber speculates. He also notes that the polymer sheet portion of the device is relatively inexpensive and therefore disposable. "I think there are many applications for this sensor that we are not yet aware of," he concludes.

####

About Optical Society of America
Uniting more than 180,000 professionals from 175 countries, the Optical Society (OSA) brings together the global optics community through its programs and initiatives. Since 1916 OSA has worked to advance the common interests of the field, providing educational resources to the scientists, engineers and business leaders who work in the field by promoting the science of light and the advanced technologies made possible by optics and photonics. OSA publications, events, technical groups and programs foster optics knowledge and scientific collaboration among all those with an interest in optics and photonics. For more information, visit www.osa.org.

About Optics Express

Optics Express reports on new developments in all fields of optical science and technology every two weeks. The journal provides rapid publication of original, peer-reviewed papers. It is published by the Optical Society and edited by Andrew M. Weiner of Purdue University. Optics Express is an open-access journal and is available at no cost to readers online at www.OpticsInfoBase.org/OE.

For more information, please click here

Contacts:
Angela Stark

202-416-1443

Copyright © Optical Society of America

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Paper: "Towards a transparent, flexible, scalable and disposable image sensor using thin-film luminescent concentrators," A. Koppelhuber and O. Bimber, Optics Express, Vol. 21, Issue 4, pp. 4796-4810 (2013):

Related News Press

News and information

Three-dimensional graphene: Experiment at BESSY II shows that optical properties are tuneable May 24th, 2017

Leti to Demo 1st Wireless UNB Transceiver for ‘Massive Internet of Things’ at RFIC 2017 and IMS 2017: Leti Will also Present Three Papers & Two Workshops on 5G Communications IC Design, from RF to mm-Wave, During IMS 2017 and RFIC 2017 in Hawaii May 24th, 2017

GLOBALFOUNDRIES and Chengdu Partner to Expand FD-SOI Ecosystem in China: More than $100M investment to establish a center of excellence for FDXTM FD-SOI design May 23rd, 2017

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Thin films

Discovery of new transparent thin film material could improve electronics and solar cells: Conductivity is highest-ever for thin film oxide semiconductor material May 6th, 2017

MIT Energy Initiative awards 10 seed fund grants for early-stage energy research May 4th, 2017

Nanomechanics, Inc. Unveils New Product at ICMCTF Show April 25th: Nanoindentation experts will launch the new Gemini that measures the interaction of two objects that are sliding across each other – not merely making contact April 21st, 2017

Nanomechanics Inc. President Warren Oliver, PhD to Present at ICMCTF: Nanoindentation experts will discuss new testing system that measures the interaction of two objects that are sliding across each other – not merely making contact April 17th, 2017

Sensors

'Hot' electrons don't mind the gap: Rice University scientists find nanogaps in plasmonic gold wires enhance voltage when excited May 8th, 2017

Better living through pressure: Functional nanomaterials made easy April 19th, 2017

A Sensitive And Dynamic Tactile Sensor Read more from Asian Scientist Magazine at: https://www.asianscientist.com/2017/04/tech/tactile-3d-active-matrix-sensor/ April 18th, 2017

AIM Photonics Presents Cutting-Edge Integrated Photonics Technology Developments to Packed House at OFC 2017, the Optical Networking and Communication Conference & Exhibition April 11th, 2017

Discoveries

Three-dimensional graphene: Experiment at BESSY II shows that optical properties are tuneable May 24th, 2017

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Sensors detect disease markers in breath May 19th, 2017

Graphene-nanotube hybrid boosts lithium metal batteries: Rice University prototypes store 3 times the energy of lithium-ion batteries May 19th, 2017

Announcements

Three-dimensional graphene: Experiment at BESSY II shows that optical properties are tuneable May 24th, 2017

Leti to Demo 1st Wireless UNB Transceiver for ‘Massive Internet of Things’ at RFIC 2017 and IMS 2017: Leti Will also Present Three Papers & Two Workshops on 5G Communications IC Design, from RF to mm-Wave, During IMS 2017 and RFIC 2017 in Hawaii May 24th, 2017

GLOBALFOUNDRIES and Chengdu Partner to Expand FD-SOI Ecosystem in China: More than $100M investment to establish a center of excellence for FDXTM FD-SOI design May 23rd, 2017

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Photonics/Optics/Lasers

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Plasmon-powered upconversion nanocrystals for enhanced bioimaging and polarized emission: Plasmonic gold nanorods brighten lanthanide-doped upconversion superdots for improved multiphoton bioimaging contrast and enable polarization-selective nonlinear emissions for novel nanoscal May 19th, 2017

Gas gives laser-induced graphene super properties: Rice University study shows inexpensive material can be superhydrophilic or superhydrophobic May 15th, 2017

Researchers develop transistors that can switch between two stable energy states May 9th, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project