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 Omron Electronic Components has extended its non-contact MEMS thermal sensor range with a new narrow-field version specifically designed to provide accurate non-contact measurements of an objects’ surface temperature for industrial control, medical and building automation systems. Omron is relaunching its full range of MEMS thermal sensors in Europe, including wider field versions ideal for detecting room occupancy and similar applications.   The new Omron D6T-1A-02 is a super-sensitive infra-red (IR) temperature sensor that makes full use of proprietary Omron MEMS sensing technology. It can measure the surface temperature of an object between -40 up to +80°C in the target area with an accuracy of +/-1.5°C and a resolution of 0.06°C.  The device includes a state-of-the-art MEMS thermopile, a sensor ASIC (Application Specific Integrated Circuit) and a signal processing microprocessor in a tiny package of only 12.0mm x 11.6mm x 9.2mm. The D6T-1A-02 features a narrow field of view of 26.5 degrees square, allowing it to accurately assess the surface temperature of a specific object in this area. Features also include a digital I2C output which offers excellent noise immunity (measured as noise equivalent temperature difference) of 140mK. The Omron D6T thermal sensor is also ideal for building automation applications, measuring the temperature in a room, or detecting occupancy even when people are stationary. For these applications, Omron is offering versions with a wider field of view. These include a 1x1 device, the D6T-1A-01, with a field 58 degrees square. A 4x4 version and a 1x8 version are also available. These ultra-sensitive sensors are an outstanding alternative to pyroelectric sensors or PIR detectors in home automation, building automation, healthcare, security and industrial applications, which often fail to distinguish between an unoccupied space and a stationary person. While standard thermal sensors are only able to measure temperature at one contact point, the D6T range can measure the temperature of an entire area contactlessly. Signals generated by infrared rays are extremely weak. To achieve reliable detection, Omron has developed and manufactured every part of the new high sensitivity thermal sensor in-house, from the MEMS sensors to the ASICs and other application-specific parts. The technology behind Omron’s D6T thermal sensors combines a MEMS micro-mirror structure for efficient IR radiation detection with a high-performance silicon lens to focus the infrared rays onto its thermopiles. The ASIC then uses proprietary algorithms to make the necessary computations and convert sensor signals into digital I2C outputs. All components were developed in-house and are fabricated in Omron’s own MEMS facilities. Ref.KY66-G6SK-2-DC5KY66-G5LA-14-DC5

Detecting temperature is an important function of skin. Snakes can use their skin to track warm-blooded prey, even in the dark. Now a highly sensitive, flexible sensor film could also make this characteristic available for robots and prosthetics. Whether in factories, the office or the kitchen: Robots continue to encroach on various aspects of our lives. When it comes to safety, that increases requirements for the “man-machine interface” considerably. Which is why developing sensitive robot skins has become a hot topic in robot research. After all, “collisions” can only be avoided if you can “see” your counterpart—as quickly and accurately as possible. Methods for doing so range from image processing using mechanical devices to contact-free sensor solutions. For example, scientists at the Technical University of Munich (TUM) have been working on artificial skin made of small hexagon plates with infrared, temperature and acceleration sensors. The infrared sensors register when things come close to the robot. Researchers at ETH Zurich and the California Institute of Technology (Caltech) are pursuing a more natural approach. Their temperature sensor is based on the plant material pectin. Like the snake’s extremely sensitive pit organ that can sense a mammal’s warm body up to a meter away, it can precisely measure temperatures to one hundredth of a degree. That is twice as sensitive as human skin.(A highly sensitive sensor film for robots measures temperatures with an accuracy of one hundredth of a degree. .)(Image: Caltech) “Cyber wood” as a temperature sensorDiscovering the artificial “snake organ” was actually a coincidence. It turns out that the electrical conductivity of cell walls in trees depends on temperature. That is because of the plant material pectin, which can also be used in the kitchen as a gelling agent for puddings and jams. Measurements that were taken on a type of “cyber wood” made of pectin and carbon nanotubes revealed that the higher the temperature, the more free calcium ions were formed at the contact points between two sugar molecules. Electrical conductivity increases proportionally. That is how the sensor idea was born. All that was missing was the “skin”. The answer: A 20-micrometer-thick film made of simple pectin gel laced with a calcium solution. Safe human-robot collaborationInitial testing revealed that the ultrathin transparent film that can be formed into nearly any shape can measure temperatures from 10 to 50 degrees Celsius with a precision of one hundredth of a degree. Supposedly, the “prey” that was used was a teddy bear—fresh from the microwave. To spatially resolve hot or cold sensations like human skin, researchers attached several electrodes along the long and short sides of a piece of “skin” measuring 25 square centimeters. The resulting grid made it possible to determine the position of temperature changes at specific locations. The “snake skin” is extremely easy to make and is more robust and less prone to interference than existing flexible temperature sensors equipped with transistors. After improving the computer algorithms used to analyze the electrode signals and improving the electrical contacts, the “snake skin” should be ready for a field trial in robotics or prosthetics. Ref.KY32-DS18B20KY45-LM61CIM3XKY45-LM35DT

As we push the limits of agriculture to feed more people in a warmer world, we do not understand how plants sense temperature.In a surprising turn of events scientists have just learned that plant light sensors also respond to temperature.Plants contain specialized light-sensitive proteins that change shape when they absorb light, much as do the photopigments in the human eye. All plants have three main red-light photoreceptors, called phytochrome A, B and C.As part of an effort to create plants that can tolerate different growth conditions, Richard Vierstra the George and Charmaine Mallinckrodt Professor in Arts & Sciences at Washington University in St. Louis has been developing a library of phytochrome B mutants, including ones that are much more or less sensitive to light than the wild type plant.To better understand their mutant plants, the Vierstra lab shared them with Jorge J. Casal lab in Argentina where doctoral student Martina Legris grew them under a wide variety of carefully controlled conditions."We got 'weird' results that couldn't be explained unless the phytochrome we were working with was sensitive to temperature as well as light," Vierstra said.As the temperature rose, some plants exposed to constant sunlight generate less of the biologically active form of phytochrome B—not more, as you'd expect.At summer temperatures, these plants behave as though they're in dim light even though they're in bright sun.The findings will be published in the Oct. 27 issue of Science, together with a companion paper also on plant temperature sensors by a lab at the University of Cambridge in England.A switch with the jittersVierstra explains that phytochrome proteins work by switching between two forms, called Pr and Pfr.The Pr form is best at absorbing red light, which is plentiful in full sun. When it absorbs red light, phytochrome converts to the Pfr state, which is better at absorbing far-red light that dominates in shade. When the Pfr absorbs far-red light, it switches back to the Pr form.This clever little system is able to detect many different qualities of light, including the light intensity (encoded in the speed at which the molecule bounces from one form to another), and the color of the light (encoded by the ratio of the Pfr form to the Pr form). Intensity tells a seed when to emerge from the soil and color tells the seeding when to grow tall to avoid shade."The beauty of this is you can purify the phytochromes, put them in a test tube and watch them switch forms simply by shining red or far-red light on the solutions," Vierstra said. "So they're not figments of our imagination."An hour glass that runs too fastBut this description leaves out one conversion. Pfr can convert to Pr by absorbing far-red light but also by a process called thermal reversion, which occurs without light.People thought thermal reversion worked like an hour glass, Vierstra said. As soon as the sun set, the hour glass started running, and Pfr started trickling back to the Pr form. The amount of Pfr at the end of the night then told the plant how long the night was.This is important because the length of night varies with the season, especially away from the Equator. So changes in day (and night) length helps plants to tell where they are in the seasonal cycle, which in turn helps them to flower in the right season.Nobody had been able to test the idea that thermal reversion was an hourglass, or timer, however. But as they were tinkering with phytochrome B, the Vierstra lab made phytochrome mutants that were fast reverters and ones that were slow reverters. And these mutants were among those that traveled to Argentina.When they grew the plants, the Casals lab got strange results they could understand only if thermal reversion is much faster than anyone realized; and only if the rate of reversion is very sensitive to temperature. In other words, the only possible interpretationwas that phytochrome B in the wild type (unmodified) plant is a temperature as well as light sensor."The plant is looking for Pfr, which tells it the light is on," said Vierstra. "In sunlight a plant slowly makes more and more Pfr until the reaction that converts Pr to Pfr saturates. But as the temperature rises, the thermal reversion starts running so fast, the plants accumulate relatively little Pfr."You would expect that at higher temperatures the Pr -> Pfr reaction would go faster," Vierstra said, "and it probably does, but thermal reversion goes even faster. It erases the light signal because the reversion reaction is more sensitive to temperature than the one creating the light signal."You can predict what this will do as temperature rises," Vierstra said. "Plants that make lots of Pfr are short, intensely green and happy. But thermal reversion will draw down the Pfr at higher temperatures, so that plants will respond as if they are in the dark (even though they are in the light) and grow tall and leggy.""We don't yet know right now whether it's just phytochrome B that's a temperature sensor," Vierstra said. So right now members of his team, including Research Scientist Sethe Burgie, are trying to get accurate measurement on the other phytochromes. "Once we have this figured out, we could make mutants that are less or more sensitive to temperature by modifying thermal reversion."Coming in from the cold"Phytochromes are the worst to work on," Vierstra said. "You have to spend four days in the dark to purify them. They are incredibly unstable, they are present at very low levels, and they have got all kinds of variants. And unlike most other proteins, their amino-acid sequences also don't tell us how phytochromes work."So when people purify phytochromes, they want to keep the proteins as happy as possible and that means keeping them as cold as possible. All the experiments are done on ice!"And that's why we didn't realize until now that phytochromes could act as temperature sensors!"Reference:LM50BIM3/NOPBLM61CIM3XTMP03FT9Z