Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Monitoring food with millimeter waves

01.12.2011
We may be able to see through glass, water and air, but not packing paper, plastic or cardboard. What remains hidden from the human eye is made visible by a new millimeter-wave sensor: unlike x-ray scanners, it can see through non-transparent materials without sending out harmful rays.

Has the packet been properly filled? Are there impurities in the chocolate? Have the plastic seams been welded correctly? Is there a knife hidden in the parcel? Answers to all these questions are provided by SAMMI, short for Stand Alone MilliMeter wave Imager. The millimeter-wave sensor is able to see through all non-transparent materials. Researchers at the Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR in Wachtberg have developed the device, whichat 50 centimeters wide and 32 centimeters high is no larger than a compact laser printer.


The millimeter-wave sensor can look through all non-transparent, non-metallic materials. © Fraunhofer FHR

SAMMI can happily deal with all non-metallic materials. “The system detects wooden splinters lurking in diapers, air pockets in plastic, breaks in bars of marzipan, and foreign bodies in foodstuffs. It can even detect and monitor the dehydration process in plants and how severely they have been stressed by drought,” says Dr. Helmut Essen, head of the FHR’s millimeter-wave radar and high-frequency sensors department. This makes the scanner extremely versatile – it’s just as suitable for industrial product and quality control as for analyzing materials in the laboratory. Because the system can detect dangerous substances such as explosive powder hidden in letters, vulnerable people such as politicians or freight handlers can be protected by millimeter-wave radar.

SAMMI’s most striking feature is its ability to pick out the smallest differences in materials – differences that are invisible to x-rays. SAMMI can for example differentiate between the different fillings of chocolates, or between rubber composites that have similar or identical absorption qualities. Another advantage is that the scanner doesn’t employ ionizing radiation, which can damage health. It is also low-maintenance, not requiring the regular checks necessary with x-ray tubes.

But how does SAMMI work? Inside the system’s housing, there is both a transmitting and a receiving antenna on each of two opposing rotating plates. A conveyor belt transports the sample – perhaps a package whose contents are unknown – between the antennae, while these send electromagnetic waves in a high frequency of 78 GHz. Different areas of the sample absorb the signal to different degrees, leading the varying material composition across a sample to show up in distinguishable contrast. “Basically we examine the scanned objects for dissimilarities,” explains Essen. The content of the sample appears in real time on the scanner’s fold-out display. If the package contains a knife, even the grain of the handle is discernible. If the handle is hollow, the millimeter-wave sensor would show that, too. The device scans an area of 30 x 30 centimeters in just 60 seconds.

Our system can be operated without safety precautions or safety instructions, and since it weighs just 20 kilograms it’s eminently portable. It can also be adjusted to various measuring frequencies,” the scientist points out. In future, the researchers aim to “upgrade” the system for terahertz frequencies of 2 THz. “Then we’ll be in a position not just to detect different structures but also to establish which type of plastic a product is made from. That’s not possible at the moment,” says Dr. Essen.

At present, SAMMI is only suitable for spot checks. However, the FHR researchers are working on adapting the millimeter-wave sensor for industrial assembly lines for the fast, automatic inspection of goods. They envision mounting a line of sensors over the conveyor belt, so that in future products can be scanned at a speed of up to six meters per second.

Dr. Helmut Essen | Fraunhofer Research News
Further information:
http://www.fraunhofer.de/en/press/research-news/2011/december/monitoring-food-with-millimeter-waves.html

More articles from Physics and Astronomy:

nachricht Electrocatalysis can advance green transition
23.01.2017 | Technical University of Denmark

nachricht Quantum optical sensor for the first time tested in space – with a laser system from Berlin
23.01.2017 | Ferdinand-Braun-Institut Leibniz-Institut für Höchstfrequenztechnik

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Tracking movement of immune cells identifies key first steps in inflammatory arthritis

23.01.2017 | Health and Medicine

Electrocatalysis can advance green transition

23.01.2017 | Physics and Astronomy

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>