"Second Skin"; New Health Tracker

Imagine sticking a patch made of flexible electronics on your skin that could read your body temperature, monitor your blood circulation, even tell you when you need to put on sunscreen — and that wouldn't leave the skin underneath it clammy the way Band-Aids do.

A team of researchers at Northwestern University in Illinois and the University of Illinois at Urbana–Champaign say they have built such a patch, and it's about the size of a bandage. It's made of plastic and thousands of tiny liquid crystals, not unlike the ones that light upcomputer and smartphone screens. It's so flexible that it molds to the body like a second skin.

The device was made to detect changes in the temperature of the skin beneath it; the liquid crystals change color in response to body heat. There are so many crystals, some 3,600 of them, that they can actually depict a heat map, or a picture of what lies below the skin. "It's like the stuff they used to have in mood rings," said John A. Rogers, a professor of materials science at the University of Illinois whose lab collaborated on the project.

This device, however, is sophisticated enough to diagnose very real problems. The device reveals the temperature of the skin beneath it with with high precision, which is important because skin temperature reflects underlying characteristics, such as blood flow, he said. And the device presents the data in a useable format. "We can get a readout using color," Rogers told Live Science.

A temperature-sensing device that could be attached to a person's skin, and that is so unobtrusive that people forget they are wearing it, would be a great help to physicians, Rogers said. 

For example, the device could reveal problems such as poor circulation in the extremities, which can be a symptom of diabetes, or an early sign of heart disease.

The device could also be used to detect some types of injuries in the skin and tissue just underneath the sensor. This is because the tissue near an injury site generally warms up, in a sign that inflammation or infection might be on the way. The sensor could also yield information such as how hydrated the skin is, the researchers said.

To test their device, the researchers attached a small antenna with the sensor, as well as a heating element. They sent a signal to the antenna to turn on the heating element, and found they could measure the distribution and diffusion of that heat through the skin and tissue.

It's possible that researchers could add other kinds of sensors to the device, too. For example, an ultraviolet light sensor combined with a sensor for moisture could alert the wearer that they are in danger of getting sunburned, for instance if the UV levels are high and the skin is becoming dry and hot.

And because the device allows air to pass through it, the skin beneath the sensor can "breathe." That means users would not get the clammy sweat that accumulates under bandages, which can cause irritation, Rogers said.

The device is so small that it doesn't need a battery. There's a wireless and flexible power system on the back, which can run on power from a remote source, said Yihui Zhang, an assistant professor of civil engineering at Northwestern and one of the leaders of the research effort. 

Rogers said the cost of the device should be relatively low, since the sensor doesn't use any exotic materials or parts. "We're talking about a few dollars," he said.

The scientists are working with a Cambridge, Massachusetts-based company called MC10 Inc. to commercialize the technology.

A paper outlining the research appeared in the Sept. 19 issue of the journal Nature Communications.

Check out the Whirly Thing!

Ryan Kunde is a winemaker whose family’s picture-perfect vineyard nestles in the Sonoma Valley north of San Francisco. But Kunde is not your average farmer. He’s also a drone operator—and he’s not alone. He’s part of the vanguard of farmers who are using what was once military aviation technology to grow better grapes using pictures from the air, part of a broader trend of using sensors and robotics to bring big data to precision agriculture.

Top: A drone from PrecisionHawk is equipped with multiple sensors to image fields.

Bottom: This image depicts vegetation in near-­infrared light to show chlorophyll levels.

What “drones” means to Kunde and the growing number of farmers like him is simply a low-cost aerial camera platform: either miniature fixed-wing airplanes or, more commonly, quadcopters and other multibladed small helicopters. These aircraft are equipped with an autopilot using GPS and a standard point-and-shoot camera controlled by the autopilot; software on the ground can stitch aerial shots into a high-­resolution mosaic map. Whereas a traditional radio-­controlled aircraft needs to be flown by a pilot on the ground, in Kunde’s drone the autopilot (made by my company, 3D Robotics) does all the flying, from auto takeoff to landing. Its software plans the flight path, aiming for maximum coverage of the vineyards, and controls the camera to optimize the images for later analysis. The advent of drones this small, cheap, and easy to use is due largely to remarkable advances in technology: tiny MEMS sensors (accelerometers, gyros, magnetometers, and often pressure sensors), small GPS modules, incredibly powerful processors, and a range of digital radios. All those components are now getting better and cheaper at an unprecedented rate, thanks to their use in smartphones and the extraordinary economies of scale of that industry. At the heart of a drone, the autopilot runs specialized software—often open-source programs created by communities such as DIY Drones, which I founded, rather than costly code from the aerospace industry.

Drones can provide farmers with three types of detailed views. First, seeing a crop from the air can reveal patterns that expose everything from irrigation problems to soil variation and even pest and fungal infestations that aren’t apparent at eye level. Second, airborne cameras can take multispectral images, capturing data from the infrared as well as the visual spectrum, which can be combined to create a view of the crop that highlights differences between healthy and distressed plants in a way that can’t be seen with the naked eye. Finally, a drone can survey a crop every week, every day, or even every hour. Combined to create a time-series animation, that imagery can show changes in the crop, revealing trouble spots or opportunities for better crop management. It’s part of a trend toward increasingly data-driven agriculture. Farms today are bursting with engineering marvels, the result of years of automation and other innovations designed to grow more food with less labor. Tractors autonomously plant seeds within a few centimeters of their target locations, and GPS-guided harvesters reap the crops with equal accuracy. Extensive wireless networks backhaul data on soil hydration and environmental factors to faraway servers for analysis. But what if we could add to these capabilities the ability to more comprehensively assess the water content of soil, become more rigorous in our ability to spot irrigation and pest problems, and get a general sense of the state of the farm, every day or even every hour? The implications cannot be stressed enough. We expect 9.6 billion people to call Earth home by 2050. All of them need to be fed. Farming is an input-­output problem. If we can reduce the inputs—water and pesticides—and maintain the same output, we will be overcoming a central challenge.

Agricultural drones are becoming a tool like any other consumer device, and we’re starting to talk about what we can do with them. Ryan Kunde wants to irrigate less, use less pesticide, and ultimately produce better wine. More and better data can reduce water use and lower the chemical load in our environment and our food. Seen this way, what started as a military technology may end up better known as a green-tech tool, and our kids will grow up used to flying robots buzzing over farms like tiny crop dusters.

Genome Editing

Until recently, Kunming, capital of China’s southwestern Yunnan province, was known mostly for its palm trees, its blue skies, its laid-back vibe, and a steady stream of foreign backpackers bound for nearby mountains and scenic gorges. But Kunming’s reputation as a provincial backwater is rapidly changing. On a plot of land on the outskirts of the city—wilderness 10 years ago, and today home to a genomic research facility—scientists have performed a provocative experiment. They have created a pair of macaque monkeys with precise genetic mutations.

Last November, the female monkey twins, Mingming and Lingling, were born here on the sprawling research campus of Kunming Biomedical International and its affiliated Yunnan Key Laboratory of Primate Biomedical Research. The macaques had been conceived via in vitro fertilization. Then scientists used a new method of DNA engineering known as CRISPR to modify the fertilized eggs by editing three different genes, and they were implanted into a surrogate macaque mother. The twins’ healthy birth marked the first time that CRISPR has been used to make targeted genetic modifications in primates—potentially heralding a new era of biomedicine in which complex diseases can be modeled and studied in monkeys.

CRISPR, which was developed by researchers at the University of California, Berkeley, Harvard, MIT, and elsewhere over the last several years, is already transforming how scientists think about genetic engineering, because it allows them to make changes to the genome precisely and relatively easily (see “Genome Surgery,” March/April). The goal of the experiment at Kunming is to confirm that the technology can create primates with multiple mutations, explains Weizhi Ji, one of the architects of the experiment.

Ji began his career at the government-affiliated Kunming Institute of Zoology in 1982, focusing on primate reproduction. China was “a very poor country” back then, he recalls. “We did not have enough funding for research. We just did very simple work, such as studying how to improve primate nutrition.” China’s science ambitions have since changed dramatically. The campus in Kunming boasts extensive housing for monkeys: 75 covered homes, sheltering more than 4,000 primates—many of them energetically swinging on hanging ladders and scampering up and down wire mesh walls. Sixty trained animal keepers in blue scrubs tend to them full time.