Almost a week ago, I briefly discussed how the world of sensors isn’t the one you see on television, certainly not what you see on any incarnation of Star Trek.
This doesn’t mean there isn’t a lot of new sensor technology coming down the pike, though.
First, a passive sensor that can image a wide variety of objects. A passive sensor doesn’t require a probe such as a radio wave (aka RADAR) or a laser beam (as mentioned in my previous post) or X-rays for detection. While the terminology isn’t common, I typically refer to active sensors as “scanners” instead, to give a clear differentiation.
Sensor Could Detect Concealed Weapons Without X-rays
Source: Ohio State University
Date: 2005-08-18
COLUMBUS , Ohio - A new sensor being patented by Ohio State University could be used to detect concealed weapons or help pilots see better through rain and fog.
Unlike X-ray machines or radar instruments, the sensor doesn’t have to generate a signal to detect objects - it spots them based on how brightly they reflect the natural radiation that is all around us every day.
There is always a certain amount of radiation - light, heat, and even microwaves - in the environment. Every object - the human body, a gun or knife, or an asphalt runway - reflects this ambient radiation differently.
Paul Berger, professor of electrical and computer engineering and physics at Ohio State and head of the team that is developing the sensor, likened this reflection to the way glossy and satin-finish paints reflect light differently to the eye.
Once the sensor is further developed, it could be used to scan people or luggage without subjecting them to X-rays or other radiation. And if the sensor were embedded in an airplane nose, it might help pilots see a runway during bad weather.
The Ohio State sensor isn’t the only ambient radiation sensor under development, but it is the only one Berger knows of that is compatible with silicon - a feature that makes it relatively inexpensive and easy to work with.
This compatibility with silicon is key.
The computer you are using to read this now is a product of decades of development in the manipulation of silicon.
Here is some perspective: It is a part of my job every day to build structures on silicon and out of silicon that are smaller than the average influenza virus. These structures contain films that are five atoms thick.
And I’m expected to come up with ways of doing this that are inexpensive enough that you can buy your cell phone for less than $20, a handheld piece of disposable equipment with more processing power than the computers used to help design the first atomic bomb or navigate or the moon.
From January of this year, another development that is an outgrowth of the techniques we have developed to make computer chips smaller and faster:
Tiny, Atom-based Detector Senses Weak Magnetic Fields
Source: National Institute Of Standards And Technology (NIST)
Date: 2005-01-07
A low-power, magnetic sensor about the size of a grain of rice that can detect magnetic field changes as small as 50 picoteslas - a million times weaker than the Earth’s magnetic field - has been demonstrated by researchers at the National Institute of Standards and Technology (NIST). Described in the Dec. 27 issue of Applied Physics Letters,* the device can be powered with batteries and is about 100 times smaller than current atom-based sensors with similar sensitivities, which typically weigh several kilograms (about 6 pounds).
The new magnetic sensor is based on the principles of a NIST chip-scale atomic clock, announced in August 2004. Expected applications for a commercialized version of the new sensor could include hand-held devices for sensing unexploded ordnance, precision navigation, geophysical mapping to locate minerals or oil, and medical instruments.
Like the NIST chip-scale clock, the new magnetic sensor can be fabricated and assembled on semiconductor wafers using existing techniques for making microelectronics and microelectromechanical systems (MEMS). This offers the potential for low-cost mass production of sensors about the size of a computer chip. When packaged with associated electronics, the researchers believe the mini magnetometer will measure about 1 cubic centimeter or about the size of a sugar cube.
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*P. Schwindt, S. Knappe, V. Shah, L. Hollberg, J. Kitching, L. Liew, J. Moreland. “Chip-scale atomic magnetometer.” Applied Physics Letters. 27 Dec. 2004
Perhaps that tricorder on Star Trek isn’t so far-fetched after all…
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