ThruVision T5000 security system sees through clothing

ThruVision’s T5000 Security Imaging System uses passive terahertz imaging technology to reveal concealed weapons in both stationary and mobile subjects, and at a range of up to 25 meters. T-rays can pass through clothing, paper, cardboard, wood, masonry, fog and clouds, but bounce off metal, liquid, and some ceramics and plastics – this allows the T5000 to easily identify weapons even in a moving crowd of people.

Terahertz radiation is the band in the electromagnetic spectrum between high-frequency microwave and long-wavelength infrared light. Because it is non-ionizing, it does not have a damaging effect on tissue and DNA like X-rays, making it potentially very useful to the security and medical industries.

Extending the range and adding outdoor capabilities to its predecessor the T4000, the T5000 is the only commercially available camera of its kind, and is compact, rugged and portable. Capable of operating in both indoor and outdoor environments, the system can be used for a variety of scenarios, including corporate protection, event management, and military and border security. The speed with which it scans an area prevents it from creating unnecessary queues and bottlenecks, making it effective in sporting events, concerts and airports, and it integrates with existing security systems, making it easy to install in corporate environments.

Clive Beattie, ThruVision’s CEO said: “Acts of terrorism have shaken the world in recent years and security precautions have been tightened globally. The T5000 dramatically extends the security surveillance envelope for ThruVision’s passive body scanning products used at important sites and events. The ability to see both metallic and non-metallic items on people out to 25m is certainly a key capability that will enhance any comprehensive security system deployment.” Dr Liz Towns-Andrews, Director of Knowledge Exchange at STFC said: “Astronomers use T-ray cameras that can see through dust and clouds in space, revealing what lies beyond. ThruVision uses them to see weapons hidden by clothing. This is a first-class example of how fundamental scientific research can be applied to benefit the whole of society. Who would have imagined that research carried out by space scientists to study the stars could result in it being used to protect the public from terrorists and therefore save lives? The impact of this will be remarkable.“

The ThruVision’s T5000 Security Imaging System is being launched at the Home Office Scientific Development Branch Exhibition, on March 12 and 13.

More-Efficient OLED Lighting

Energy efficiency and flexible lighting applications have long been the promise of organic light emitting diodes (OLEDs). The technology hasn't lived up to its promise, however, because in typical OLEDs, only 20 percent of the light generated is released from the device. That means that most light is trapped inside the bulb, making it highly inefficient.

Researchers at the University of Michigan and Princeton University believe that they're on to a way to break the OLED-efficiency logjam. The scientists have designed an OLED that boosts illumination by 60 percent using a combination of an organic grid working in tandem with small micro lenses that guide the trapped light out of the device.

Beam me up: A new OLED design could help the devices emit far more light. Electron microscope images show the top of
the OLED with organic and aluminum layers (top) and an organic grid before depositing the organic and aluminum

layers (middle). The bottom image shows polymer micro lenses on the surface of the glass substrate.Credit: University of Michigan/Nature Photonics

Stephen Forrest, a professor of electrical engineering and physics at Michigan, and Yuri Sun, from Princeton University, described the work in the August issue of Nature Photonics.
In OLEDs, white light is generated by using electricity to send an electron into nanometer-thick layers of organic materials that behave like semiconductor materials. Typically, the light in the substrate is internally reflected and runs parallel and not perpendicular. That's the crux of the problem because the light can't escape in the vertical direction without some coaxing. In Forrest's devices, the grids refract the trapped light, sending it to the five micrometers dome-shaped micro lenses. The light is sent off in a vertical orientation that helps release the trapped rays.

Forrest and his coworkers report that the technology emits about 70 lumens from a watt of power. In comparison, incandescent lightbulbs emit 15 lumens per watt. Fluorescent lights put out roughly 90 lumens of light per watt but have liabilities: they produce harsh light, lack longevity, and use environment-damaging substances like mercury. Forrest says that the next step in the research is to use OLEDs that are more efficient than those the team used in
the current project. Looking beyond the research lab work on these OLEDs, he is cautiously optimistic that it should be possible to scale up the manufacturing of the devices, and that production costs for manufacturing the new OLEDs will be competitive.

Today, an estimated 22 percent of the electricity produced goes to lighting buildings. A highly efficient form of OLED lighting could significantly reduce the electricity demand and boost savings. Another factor influencing broad adoption of LEDs is the fact that they outlast incandescent bulbs. Over the next 20 years, the rapid adoption of LED lighting in the United States could reduce electricity demands by 62 percent and thus eliminate 258 million metric
tons of carbon emissions, according to the Department of Energy.

It will take several years to replace current lighting in office buildings and homes with OLEDs. But the continued progress in increasing the efficiencies of the devices is encouraging to researchers. "Luckily, OLEDs are the light that just keeps giving," says Forrest, who has spent much of his professional research career focused on OLEDs. "There is so much to be done and so much that's been done, but this is nonetheless a quite exciting advancement."