See through smoke and fog, map a person’s blood vessels while monitoring heart rate – without skin contact; look through the silicon wafers to check the quality and composition of the electronic board. Those are some of the many functions of infrared camera new, developed by a team of researchers led by electrical engineers at the University of California San Diego. The camera detects a part of the infrared spectrum known as shortwave infrared light (wavelengths between 1000 and 1400 nanometers), which lies just outside the visible spectrum (400 to 700 nanometers). Shortwave infrared imaging, unlike thermal imaging, detects much longer infrared wavelengths emitted by the body. The camera works by shining short-wave infrared light at an object or area of ​​interest, then converting the reflected low-energy infrared light back to the device into shorter, high-energy wavelengths. than the human eye can see. “It makes invisible light visible,” said Tina Ng, professor of electrical and computer engineering at UC San Diego Jacobs School of Engineering. When technology Infrared imaging has been around for decades, where most systems are expensive, cumbersome, and complex, often requiring a separate camera and monitor. They are also often made with inorganic semiconductors, which are expensive, hard, and contain toxic elements such as arsenic and lead. The infrared camera that Ng’s team has developed overcomes these problems. It combines sensors and display into a slim, compact and simple device. It is made of organic semiconductors, so it is low cost, flexible and safe for use in biomedical applications. It also offers better image resolution than some of its inorganic versions. The camera is made up of multiple layers of semiconductors, each hundreds of nanometers thin, stacked on top of each other. Three of these layers, each made of a different organic polymer, are the key elements of the image: the photodetector layer, the organic light-emitting diode (OLED) display layer, and the blocking layer. electrons in the middle. The photodetector layer absorbs shortwave infrared light (low energy photons) and then generates an electric current. This current flows to the OLED display layer, where it is converted into a visible image (high-energy photons). An intermediate layer, called an electron block, keeps the OLED display layer from losing any current. This is what allows the device to produce clearer images. Another special feature is camera effective in providing optical and electronic indicators. “This makes it multifunctional,” says Li. For example, when the researchers shined infrared light on the back of the subject’s hand, the camera provided an image of the subject’s blood vessels while recording the subject’s heart rate. The researchers also used their infrared camera to see through the fog and a silicon wafer. In one test, they placed an “EXIT” patterned photosphere in a small room filled with smog. In another setting, they placed a photorealist patterned “UCSD” behind a silicon wafer. Infrared light penetrates both smog and silicon, making it possible for the imagineer to see the letters in these illustrations. This would be useful for applications such as helping self-driving cars see in bad weather and checking for silicon faults. The researchers are currently working to improve the performance of this type of camera.

Illustration. My hometown was in the midland hills, at that time the grass was green. The message canopy ran across the hillsides. Under the forest canopy is a world of grass, flowers, myrtle, mussels, peonies… four seasons blooming. On the top of the mountain, there are sparse trees and grass that grow in places. Perched by the gray rocks, the thorny bushes stretched out their green arms in the scorching summer sun. We used to climb hills to rake pine needles, find ripe myrtle and pick leaves from those bushes. People call it the palm tree. I was too young at that time, and I don’t remember who drew it for me. I just know that I can go with my brothers and sisters to the mountains, climb like a baby goat, jump on each cliff to pick leaves, pick but not cut even though the tree has sparse thorns and bleeds. And only pick the leaves of the cake, not too old, not too young. My grandmother said to make delicious jelly and let the tree live for everyone to pick. I like the cool scent of the leaves. Sometimes, after picking, we would run around looking for wild fruits or sit on a large rock, while blooming the leaves, we would look at the village and the tiny river in the distance, holding out our little hands. embracing the sweat-drying face, welcoming the fragrant breezes blowing from the vast fields, dreaming… I love that hill! Love the young pine buds that build green towers lined up on the slopes, the fragrant pine like candles in the sky! Love the giants, grasshoppers and big elephants kicking the brakes, dancing and throwing leaves! Love the sound of howling birds, “catching shrimp braised” in the sky and the cuckoo calling from afar… But love the hill most in the ripe fruit season. Juicy red raspberries in the humid valley by the rocky crevice, clusters of sweet red-purple peonies; The sedum vine hangs tiny purple-pink fruit eyes, black alum, black pearl soup mixed with thorns and inviting thorns… The most interesting thing is that sometimes you open your nose to find the faint scent of ripe fruit, then turn the grass and trees, and catch the flowers. tufts of passion fruit charm or sweet chestnut flowers, sniffing to forget the hungry stomach… Sometimes, our children try to pick sour leaves and acrid fruits to eat. Small green cow’s udder oozes milk, small pomelos, pink and pink, transparent, fragrant, spicy… even the whole fruit is bought full of seeds and tasted… Myrtle season is a paradise for children. Just the other day, the eye-catching purple-pink petals swaying in their hands, in the hair of a few children braided in pigtails, now they turn into fruit while hanging on the branches, showing off their sweet and inviting purple belly… purple and purple… The smiles of children in the mountains and forests… The midland hills gave us delicious food, sweet fruits, raised poor children to grow up in body and soul. I often hum the rhymes as I weave my way through the sparse shrubs or bend down to pick up the pine cones rolling on the carpet of fragrant leaves. In order to remember my homeland later, I often call this the singing hill: There are blue winds Fly through the forest of childhood Where is the sweetness and sweetness Mourning purple sim hillside… Only a song left Keep flying in the nostalgia Wings of time once Wet soft clear spring water… There are steep mountain slopes Sweet white gardenia There is a pine forest that screams I lie on a carpet of fragrant leaves… Miss the misty mountain valley There are wings of clouds and the head of the wind Herd of buffaloes grazing on grass Flowers to open eyes purple pink… From the top of the immense mountain Zoom in on all four sides Seeing the small village far away Loving the old bamboo ramparts… Back to the past years Seeing the kite flying enthusiastically Seeing fragrant sweet potato buried in the kitchen Locusts, grasshoppers fly back… I love summer days Wandering in search of the smell of ripe fruit Sweet wild fruit in the mouth Sorrel leaves in the forest… Fascinated white flower rose Chirping birdsong at the top of the mountain Confused yellow butterfly wings Clap the flash of childhood… … Every time I go to the hill to pick leaves, I like it, even making jelly at home is really fun. Before that, the elder brothers or sisters or grandmothers had prepared a large pot of water to cool, a small pot of sugar syrup, sometimes just begging or hiding some sugar from the house because sugar was scarce that day, sometimes a few drops. sugar cane or holding grass roots… Glove leaves are washed many times by us, drained, dried slightly and then put in a large pot or saucepan to crush with our hands. I remember once, we even washed a pair of rubber slippers and used them as a grinding table, rubbing the leaves vigorously. When the leaves have turned into a green powder, they are wrapped in a white coarse cloth and then dipped in a pot of boiling water to cool, thoroughly dried, and squeezed out. Sometimes, we squeeze in a little bit of clear lime juice from the lime pot she eats betel nut, sometimes we don’t, but it only takes a few minutes for the pot to solidify. Sometimes to cool more, the brothers and sisters take a piece of rain cloth to cover the jelly pot and then the line is dropped to the bottom of the well, a few hours later or overnight to pull it up. Wow, it’s delicious when the green jelly pieces are cut out, dropped into a cup or bowl of sugar water, sprinkled with a little banana or grapefruit essential oil! Sometimes it’s not so “advanced”, my brothers and sisters boil some sugarcane juice, stevia roots, sprinkle some sugar obtained on the jelly and then compete to eat… Wherever you eat, cool your guts, cool your liver there, although there is not enough sweetness to mask the strong smell of fresh leaves. So many years have passed, I still remember the afternoons full of flowers and sunshine under the rustling bamboo shade, we slurped the bowls of cool green jelly like jade. Delicious dishes with a hilly flavor but even more delicious by their own hands. It’s even more delicious when receiving the sparkling smiles of grandmothers and mothers when enjoying the jelly that our children prepare… For decades, I have not returned to that ancient hill country. I don’t know if jelly gloves, sims buy… are there any trees left or erased over the years along with the soaring pine forests for a while. But in me, the grassy hills sing with the flavors of wild fruits, fragrant leaves, the first transparent, green jelly slice I ate… still remain forever in the memory and follow through life!