No-Sweat Pressure Sensors.

The new pressure sensor works at temperatures of up to 250 degrees Celsius. (Credit: Copyright Fraunhofer IMS)

Source: ScienceDaily

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ScienceDaily (Jan. 13, 2010) — Microelectronic chips used to take pressure readings are very delicate. A new technology has been developed that makes pressure sensors more robust, enabling them to continue operating normally at temperatures up to 250 degrees Celsius.

The drill bit gradually burrows deeper into the earth, working its way through the rock. Meanwhile, dozens of sensors are busily engaged in tasks such as taking pressure readings and evaluating porosity. The conditions they face are extreme, with the sensors being required to withstand high temperatures and pressures as well as shocks and vibrations. The sensors send the data to the surface to help geologists with work such as searching for oil deposits.
Yet there is one major hurdle: on average, the pressure sensors can only withstand temperatures of between 80 and 125 degrees Celsius -- but at great depths the temperature is often significantly higher. The Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg has come to the rescue, its researchers having developed a pressure sensor system that continues to function normally even at 250 degrees Celsius.
"The pressure sensors consist of two components that are located on a microelectronic chip or wafer," explains Dr. Hoc Khiem Trieu, department head at IMS. "The first component is the sensor itself, and the other component is the EEPROM." This is the element that stores all the readings together with the data required for calibration.
To enable the pressure sensor to function properly even at extremely high temperatures, the developers modified the wafer. While normal wafers tend to be made of monocrystalline silicon, the researchers chose silicon oxide for this application. "The additional oxide layer provides better electrical insulation," Trieu continues. "It prevents the leakage current that typically occurs at very high temperatures, which is the principal reason that conventional sensors fail when they reach a certain temperature."
The oxide layer enabled the researchers to improve the insulation of the memory component by three to four orders of magnitude. In theory, this should enable the pressure sensors to withstand temperatures of up to 350 degrees Celsius -- the researchers have provided practical proof of stability up to 250 degrees and are planning to conduct further studies at higher temperatures. In addition, the researchers are analyzing the prototypes of the pressure sensors in endurance tests.
There is a broad range of potential applications, with engineers hoping to use the high-temperature pressure sensors not only in the petrochemical environment, but also in automobile engines and geothermal applications.

Story Source:
Adapted from materials provided by Fraunhofer-Gesellschaft.

RCA's Airenergy charger converts WiFi energy to electricity (VIDEO)

Source: Physorg.com

Airenergy is a gadget that can harvest free electricity from WiFi signals such as those from a wireless Internet connection, apparently with enough efficiency to make it practical for recharging devices such as mobile phones.

At the Consumer Electronics Show (CES) in Las Vegas this week a RCA spokesman said they had been able to charge a BlackBerry from 30% charge to fully charged in around 90 minutes using only ambient WiFi signals as the power source, although it was unclear on whether the Airenergy battery was recharged in that time. The Airenergy recharging time depends on the proximity to the WiFi signal and the number of WiFi sources in the vicinity.
The RCA Airenergy unit converts the WiFi antenna signal to DC power to recharge its own internal lithium battery, so it automatically recharges itself whenever the device is anywhere near a WiFi hotspot. If you have a wireless network at home the Airenergy would recharge overnight virtually anywhere in your home. When you need to recharge your phone or other device you plug the Airenergy battery into the phone via USB to transfer the charge.

Harvesting electricity from signals in the air is not new, as anyone who ever built a crystal radio running only on the radio signals it received can testify, but until now no device has been able to harvest enough electricity to make it of practical use. In most modern cities WiFi signal hotspots abound, which might make the Airenergy device a viable option, although in rural areas WiFi sources are less widespread.
A USB charger costing around $40, and about the size of a phone, is expected to be released later this year, with a WiFi-harvesting battery around the same size and price as an OEM battery available shortly after.

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Introducing the Light Touch interactive projector.

Source: Physorg.com

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UK-based company Light Blue Optics has introduced an extremely compact projector that converts any flat surface into an interactive touch video screen.

The Light Touch interactive projector is basically a hand-held computer that runs Windows CE and uses a proprietary holographic laser projection (HLP) system to project a virtual touch screen onto any flat surface. The image projected is only 15 lumens, but remains in focus even at long distances.
Holographic refers to the method Light Blue Optics uses to create two-dimensional images by transforming original images into sets of diffraction patterns that are shown on a micro-display and then illuminated by laser light. Diffraction patterns are used because of their high efficiency, since they direct light to where it is needed rather than indiscriminately.
Multiple diffraction patterns are calculated, with each producing a rough version on the image. The viewer's eye then separates the images from the noise and sees them as a clear video image that is always in focus, even when projected onto a curved surface. The lasers produce vivid and bright image colors, and the wide throw angle produces large (10-inch) images even close to the tiny projector.

The Light Touch system detects interactivity via an integrated infrared system that in effect transforms any surface into a touch screen, and this allows users to run the projector and control applications by touching the image. WiFi connectivity and Bluetooth technology are built-in to allow users to connect to the Internet for multimedia sharing and social networking via the projector.
The laser used in the Light Touch projector is a class 1, which means it is completely eye safe, and the projected images are WVGA (Wide Video Graphics Array), which produces a crisp, auto-focused image. The standard flash memory is 2 GB, but there is a micro SD card slot to upgrade to 32 GB storage. The battery life rating is for two hours.

The Light Touch projector, the first released product of Blue Light Optics, was demonstrated for the first time on 7 January at the 2010 Consumer Electronics Show (CES) in Las Vegas.

More information: Light Blue Optics website: http://lightblueoptics.com/products/light-touch/
© 2009 PhysOrg.com

Communication Through Power Of Thought now possible,with the help of electrodes, a PC and Internet connection.

SOURCE

ScienceDaily (Oct. 6, 2009) — New research from the University of Southampton has demonstrated that it is possible for communication from person to person through the power of thought -- with the help of electrodes, a computer and Internet connection.

Brain-Computer Interfacing (BCI) can be used for capturing brain signals and translating them into commands that allow humans to control (just by thinking) devices such as computers, robots, rehabilitation technology and virtual reality environments.
This experiment goes a step further and was conducted by Dr Christopher James from the University's Institute of Sound and Vibration Research. The aim was to expand the current limits of this technology and show that brain-to-brain (B2B) communication is possible.
Dr James comments: "Whilst BCI is no longer a new thing and person to person communication via the nervous system was shown previously in work by Professor Kevin Warwick from the University of Reading, here we show, for the first time, true brain to brain interfacing. We have yet to grasp the full implications of this but there are various scenarios where B2B could be of benefit such as helping people with severe debilitating muscle wasting diseases, or with the so-called 'locked-in' syndrome, to communicate and it also has applications for gaming."
His experiment had one person using BCI to transmit thoughts, translated as a series of binary digits, over the internet to another person whose computer receives the digits and transmits them to the second user's brain through flashing an LED lamp.
While attached to an EEG amplifier, the first person would generate and transmit a series of binary digits, imagining moving their left arm for zero and their right arm for one. The second person was also attached to an EEG amplifier and their PC would pick up the stream of binary digits and flash an LED lamp at two different frequencies, one for zero and the other one for one. The pattern of the flashing LEDs is too subtle to be picked by the second person, but it is picked up by electrodes measuring the visual cortex of the recipient.
The encoded information is then extracted from the brain activity of the second user and the PC can decipher whether a zero or a one was transmitted. This shows true brain-to-brain activity.
You can watch Dr James' BCI experiment at: http://www.youtube.com/watch?v=93p7oDkA5WA&feature=email
Dr James is part of the University of Southampton's Brain-Computer Interfacing Research Programme, which brings together biomedical engineering and the clinical sciences and provides a cohesive scientific basis for rehabilitation research and management. Projects are driven by clinical problems, using cutting-edge signal processing research to produce an investigative tool for advancing knowledge of neurophysiological mechanisms, as well as providing a practical therapeutic system to be used outside a specialised BCI laboratory.
Dr James also appeared on BBC2's 'James May's Big Ideas' last year, talking about thought controlled wheelchairs and introducing the field of BCI. You can view the segment here: http://www.youtube.com/watch?v=Uyrd0uOuyms&feature=related
Adapted from materials provided by University of Southampton, via EurekAlert!, a service of AAAS.

New Multi-use Device Can Shed Light On Oxygen Intake.

SOURCE

ScienceDaily (Oct. 5, 2009) — A fiber-optic sensor created by a team of Purdue University researchers that is capable of measuring oxygen intake rates could have broad applications ranging from plant root development to assessing the effectiveness of chemotherapy drugs.

The self-referencing optrode, developed in the lab of Marshall Porterfield, an associate professor of agricultural and biological engineering, is non-invasive, can deliver real-time data, holds a calibration for the sensor's lifetime and doesn't consume oxygen like traditional sensors that can compete with the sample being measured. A paper on the device was released on the early online version of the journal The Analyst this week.
"It's very sensitive in terms of the biological specimens we can monitor," Porterfield said. "We don't only measure oxygen concentration, we measure the flux. That's what's important for biologists."
Mohammad Rameez Chatni, a doctoral student in Porterfield's lab, said the sensor could be used broadly across disciplines. Testing included tumor cells, fish eggs, spinal cord material and plant roots.
Cancerous cells typically intake oxygen at higher rates than healthy cells, Chatni said. Measuring how a chemotherapy drug affects oxygen intake in both kinds of cells would tell a researcher whether the treatment was effective in killing tumors while leaving healthy cells unaffected.
Plant biologists might be interested in the sensor to measure oxygen intake of a genetically engineered plant's roots to determine its ability to survive in different types of soil.
"This tool could have applications in biomedical science, agriculture, material science. It's going across all disciplines," Chatni said.
The sensor is created by heating an optical fiber and pulling it apart to create two pointed optrodes about 15 microns in diameter, about one-tenth the size of a human hair. A membrane containing a fluorescent dye is placed on the tip of an optrode.
Oxygen binds to the fluorescent dye. When a blue light is passed through the optrode, the dye emits red light back. The complex analysis of that red light reveals the concentration of oxygen present at the tip of the optrode.
The optrode is oscillated between two points, one just above the surface of the sample and another a short distance away. Based on the difference in the oxygen concentrations, called flux, the amount of oxygen being taken in by the sample is calculated.
It's the intake, or oxygen transportation, that Porterfield said is important to understand.
"Just knowing the oxygen concentration in or around a sample will not necessarily correlate to the underlying biological processes going on," he said.
Porterfield said future work will focus on altering the device to measure things such as sodium and potassium intake as well. The National Science Foundation funded the research.
Adapted from materials provided by Purdue University. Original article written by Brian Wallheimer.

'Visual Walkman' Offers Augmented Reality.

SOURCE

ScienceDaily (Sep. 30, 2009) — "Augmented reality" involves mixing the real world with computer-generated images. The result is a kind of visual Walkman. Jurjen Caarls developed a prototype, which is the subject of a doctoral dissertation that he recently defended at Delft Univesity of Technology (The Netherlands).

One example of augmented reality is a special helmet, in which images are projected into the wearer’s eyes, thereby creating the illusion that these images are part of reality. It is as if extra elements are being added to reality.
Football advertising
A simpler form of real-time augmented reality is already being used during televised football matches. This technology is used to create virtual billboards on either side of the goals, as an additional option for advertisers. Whatever the camera angle, these virtual billboards seem to be perfectly aligned with real on-screen objects. This is made possible by adjusting the projection of these images using information on the current ‘state’ of the live camera.
Sensors
However, things get considerably more complicated when people start moving around within an augmented reality environment. In these situations, of course, the only way to achieve acceptable results is to have accurate, moment-by-moment information on the position and orientation of the individual in question (and especially that of their eyes) relative to the real space around them. This information is fed into the system by various sensors. The equipment built into the augmented reality helmet includes a camera, angular velocity sensors, and accelerometers.
Prototype
Jurjen Caarls’ main focus was on achieving accurate, real-time measurements of position and orientation. To this end, he has developed specific image processing techniques, as well as methods for mixing and filtering the information from various sensors. In partnership with the Royal Academy of Arts in The Hague, he has successfully created a working prototype. Those using the system can simply observe the real world, or they can supplement reality with virtual objects. This effect is achieved using two small screens and two semi-transparent mirrors, which are built into the helmet.
Walkman
Caarls feels that the further development of augmented reality could lead to an entirely novel interaction between man and computer. "I can imagine a future in which people experience augmented reality by wearing glasses with integrated displays that project images on their retinas. These images will seem to be just another part of reality. Think of it as a visual Walkman," he said.
In the future, augmented reality applications could have a wide range of uses, in museums and games for example. They could also be a valuable tool for architects and industrial maintenance workers.
Adapted from materials provided by Delft University of Technology.