:-)
Posted on 05/31/2013 4:13:02 PM PDT by LibWhacker
Cameras fitted with a new revolutionary sensor will soon be able to take clear and sharp photos in dim conditions, thanks to a new image sensor invented at Nanyang Technological University (NTU).
The new sensor made from graphene, is believed to be the first to be able to detect broad spectrum light, from the visible to mid-infrared, with high photoresponse or sensitivity. This means it is suitable for use in all types of cameras, including infrared cameras, traffic speed cameras, satellite imaging and more.
Not only is the graphene sensor 1,000 times more sensitive to light than current imaging sensors found in today's cameras, it also uses 10 times less energy as it operates at lower voltages. When mass produced, graphene sensors are estimated to cost at least five times cheaper.
Graphene is only one-atom thick and is made of pure carbon atoms arranged in a honeycomb structure. It is known to have a high electrical conductivity among other properties such as durability and flexibility.
The inventor of the graphene sensor, Assistant Professor Wang Qijie, from NTU's School of Electrical & Electronic Engineering, said it is believed to be the first time that a broad-spectrum, high photosensitive sensor has been developed using pure graphene.
His breakthrough, made by fabricating a graphene sheet into novel nano structures, was published this month in Nature Communications, a highly-rated research journal.
"We have shown that it is now possible to create cheap, sensitive and flexible photo sensors from graphene alone. We expect our innovation will have great impact not only on the consumer imaging industry, but also in satellite imaging and communication industries, as well as the mid-infrared applications," said Asst Prof Wang, who also holds a joint appointment in NTU's School of Physical and Mathematical Sciences.
"While designing this sensor, we have kept current manufacturing practices in mind. This means the industry can in principle continue producing camera sensors using the CMOS (complementary metal-oxide-semiconductor) process, which is the prevailing technology used by the majority of factories in the electronics industry. Therefore manufacturers can easily replace the current base material of photo sensors with our new nano-structured graphene material."
If adopted by industry, Asst Prof Wang expects that cost of manufacturing imaging sensors to fall - eventually leading to cheaper cameras with longer battery life.
How the Graphene nanostructure works
Asst Prof Wang came up with an innovative idea to create nanostructures on graphene which will "trap" light-generated electron particles for a much longer time, resulting in a much stronger electric signal. Such electric signals can then be processed into an image, such as a photograph captured by a digital camera.
The "trapped electrons" is the key to achieving high photoresponse in graphene, which makes it far more effective than the normal CMOS or CCD (charge-coupled device) image sensors, said Asst Prof Wang. Essentially, the stronger the electric signals generated, the clearer and sharper the photos.
"The performance of our graphene sensor can be further improved, such as the response speed, through nanostructure engineering of graphene, and preliminary results already verified the feasibility of our concept," Asst Prof Wang added.
This research, costing about $200,000, is funded by the Nanyang Assistant Professorship start-up grant and supported partially by the Ministry of Education Tier 2 and 3 research grants.
Development of this sensor took Asst Prof Wang a total of 2 years to complete. His team consisted of two research fellows, Dr Zhang Yongzhe and Dr Li Xiaohui, and four doctoral students Liu Tao, Meng Bo, Liang Guozhen and Hu Xiaonan, from EEE, NTU. Two undergraduate students were also involved in this ground-breaking work.
Asst Prof Wang has filed a patent through NTU's Nanyang Innovation and Enterprise Office for his invention.
The next step is to work with industry collaborators to develop the graphene sensor into a commercial product.
:-)
Your very own portable body scanner like they had in airports.
This phrasing for comparisons always strikes me as wrong. If the CMOS one uses 500 mA, what is "ten times less" than that?
I know. Always gets me, too. They should say one-tenth.
Imagine pairing this technology with light-emitting electronics. The graphene sensors and light-emitters coating the entire surface of a vehicle. A better camoflage. One side of the vehicle (or clothing) sensing the light, and the other side emitting the same light intensity out, while reflecting the image seen back to the source of outside light coming at the vehicle. Invisibility. This has been done with existing camera technology, but very poorly. The graphene technology is more powerful whle using less energy, and will create a more seamless surface.
I remember when ASA 400 color film first came out. That was a dramatic change.
Confucius say man who need dim light camera need flashlight.
Confucius wasn’t being shot at.
I was thinking about getting a 2nd body (prob 7D) but with this coming out and the light use my 60D sees, I will stay with the 60D unless something happens to it.
Not necessarily. The ultimate limit that one can push a photodetector to is, in the final analysis, determined by "noise", not conversion efficiency. If you can reduce the "noise" to 1/1000 of its previous level, you can increase the amplification applied to the signal by that same factor. Just increasing the integration time won't help if that integration time is also accumulating "noise".
Which is why many astronomical cameras are liquid nitrogen cooled.
Perhaps for very low cost devices such as phototransistors or even many photodiodes. "Good" PIN and APD detectors have very little noise. While PMT's are routinely used for photon counting (I was detecting individual photons [less quantum efficiency] in 1970, limited only by cosmic ray events), today even APDs are able to count photons.
Photon counting cameras are also common [liquid nitrogen went out decades ago] though not cheap. While lower noise in a standard camera will always help, major factors in establishing noise levels are pixel area, geometry, quantum efficiency, detector material properties, and temperature. Still the cumulative noise is still Gaussian (for "cheap" detectors) or Poisson (for "good" detectors) so time integration reduces these statistical problems (proportional to the squareroot of the integration time), which is why I wrote what I wrote.
Claiming a better camera is fine, but not that its "1000x" more sensitive.
All cameras are necessarily photodetectors, but the reverse is not true.
The factors you list are certainly correct, but once all of those have been selected, in the final analysis, the controlling parameter is the noise level in the individual sensing element. Yes, some advantage can be gained by longer integration time, but even there, the noise is the final determinant of what is practical. Note that NASA PUT INTO ORBIT a satellite whose detector was LIQUID-HELIUM-COOLED for this very reason. The advantage in increased sensitivity in the spectral region of interest was sufficient for them to make this very radical design choice.
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