Posts belonging to Category Internet of things

How To Harness Heat To Power Computers

One of the biggest problems with computers, dating to the invention of the first one, has been finding ways to keep them cool so that they don’t overheat or shut down. Instead of combating the heat, two University of Nebraska–Lincoln engineers have embraced it as an alternative energy source that would allow computing at ultra-high temperatures. Sidy Ndao, assistant professor of mechanical and materials engineering, said his research group’s development of a nano-thermal-mechanical device, or thermal diode, came after flipping around the question of how to better cool computers.

thermal diode

If you think about it, whatever you do with electricity you should (also) be able to do with heat, because they are similar in many ways,” Ndao said. “In principle, they are both energy carriers. If you could control heat, you could use it to do computing and avoid the problem of overheating.”

A paper Ndao co-authored with Mahmoud Elzouka, a graduate student in mechanical and materials engineering, was published in the March edition of Scientific Reports. In it, they documented their device working in temperatures that approached 630 degrees Fahrenheit (332 degrees Celsius).


‘Spray-On’ Memory for Paper, Fabric, Plastic

USB flash drives are already common accessories in offices and college campuses. But thanks to the rise in printable electronics, digital storage devices like these may soon be everywhere – including on our groceries, pill bottles and even clothingDuke University researchers have brought us closer to a future of low-cost, flexible electronics by creating a new “spray-on digital memory device using only an aerosol jet printer and nanoparticle inks. The device, which is analogous to a 4-bit flash drive, is the first fully-printed digital memory that would be suitable for practical use in simple electronics such as environmental sensors or RFID tags. And because it is jet-printed at relatively low temperatures, it could be used to build programmable electronic devices on bendable materials like paper, plastic or fabric.


Duke University researchers have developed a new “spray-on” digital memory (upper left) that could be used to build programmable electronics on flexible materials like paper, plastic or fabric. They used LEDS to demonstrate a simple application.

We have all of the parameters that would allow this to be used for a practical application, and we’ve even done our own little demonstration using LEDs,” said Duke graduate student Matthew Catenacci, who describes the device in a paper published online in the Journal of Electronic Materials. At the core of the new device, which is about the size of a postage stamp, is a new copper-nanowire-based printable material that is capable of storing digital information.

Memory is kind of an abstract thing, but essentially it is a series of ones and zeros which you can use to encode information,” said Benjamin Wiley, an associate professor of chemistry at Duke and an author on the paper.


Your browsing history may be up for sale soon

A US House committee is set to vote on whether to kill privacy rules that would prevent internet service providers (ISPs) from selling users’ web browsing histories and app usage histories to advertisers. Planned protections, proposed by the Federal Communications Commission (FCC) that would have forced ISPs to get people’s consent before hawking their data – are now at risk. Here’s why it matters.

Your web browsing patterns contain a treasure trove of data, including your health concerns, shopping habits and visits to porn sites. ISPs can find out where you bank, your political views and sexual orientation simply based on the websites you visit. The fact that you’re looking at a website at all can also reveal when you’re at home and when you’re not.

spy your dataIf you ask the ISPs, it’s about showing the user more relevant advertising. They argue that web browsing history and app usage should not count as “sensitiveinformation.
Not all ISPs want to abolish the privacy protections. A list of several smaller providers – including, Cruzio Internet and Credo Mobile – have written to representatives to oppose the decision. “One of the cornerstones of our businesses is respecting the privacy of our customers,” they said.
How does this differ from the way Google and Facebook use our data?
It’s much harder to prevent ISPs from tracking your data. You can choose not to use Facebook or Google’s search engine, and there are lots of tools you can use to block their tracking on other parts of the web, for example EFF’s Privacy Badger.

Consumers are generally much more limited for choice of ISP, in some cases only having one option in a given geographical area. This means they can’t choose one of the ISPs pledging to protect user data.


Scalable Production of Conductive Graphene Inks

Conductive inks based on graphene and layered materials are key for low-cost manufacturing of flexible electronics, novel energy solutions, composites and coatings. A new method for liquid-phase exfoliation of graphite paves the way for scalable production.

Conductive inks are useful for a range of applications, including printed and flexible electronics such as radio frequency identification (RFID) antennas, transistors or photovoltaic cells. The advent of the internet of things is predicted to lead to new connectivity within everyday objects, including in food packaging. Thus, there is a clear need for cheap and efficient production of electronic devices, using stable, conductive and non-toxic components. These inks can also be used to create novel composites, coatings and energy storage devices.

A new method for producing high quality conductive graphene inks with high concentrations has been developed by researchers working at the Cambridge Graphene Centre at the University of Cambridge, UK. The novel method uses ultrahigh shear forces in a microfluidisation process to exfoliate graphene flakes from graphite. The process converts 100% of the starting graphite material into usable flakes for conductive inks, avoiding the need for centrifugation and reducing the time taken to produce a usable ink. The research, published in ACS Nano, also describes optimisation of the inks for different printing applications, as well as giving detailed insights into the fluid dynamics of graphite exfoliation.

graphene scalable production

“This important conceptual advance will significantly help innovation and industrialization. The fact that the process is already licensed and commercialized indicates how it is feasible to cut the time from lab to market” , said Prof. Andrea Ferrari, Director of the Cambridge Graphene Centre.


Wireless Power

A new method developed by Disney Research for wirelessly transmitting power throughout a room enables users to charge electronic devices as seamlessly as they now connect to WiFi hotspots, eliminating the need for electrical cords or charging cradles. The researchers demonstrated their method, called quasistatic cavity resonance (QSCR), inside a specially built 16-by-16-foot room at their lab. They safely generated near-field standing magnetic waves that filled the interior of the room, making it possible to power several cellphones, fans and lights simultaneously.


This new innovative method will make it possible for electrical power to become as ubiquitous as WiFi,” said Alanson Sample, associate lab director & principal research scientist at Disney Research. “This in turn could enable new applications for robots and other small mobile devices by eliminating the need to replace batteries and wires for charging.

In this work, we’ve demonstrated room-scale wireless power, but there’s no reason we couldn’t scale this down to the size of a toy chest or up to the size of a warehouse,” said Sample, who leads the lab’s Wireless Systems Group.

According to Sample, is a long-standing technological dream. Celebrated inventor Nikola Tesla famously demonstrated a wireless lighting system in the 1890s and proposed a system for transmitting power long distances to homes and factories, though it never came to fruition. Today, most wireless power transmission occurs over very short distances, typically involving charging stands or pads.

The QSCR method involves inducing electrical currents in the metalized walls, floor and ceiling of a room, which in turn generate uniform magnetic fields that permeate the room’s interior. This enables power to be transmitted efficiently to receiving coils that operate at the same resonant frequency as the magnetic fields. The induced currents in the structure are channeled through discrete capacitors, which isolate potentially harmful electrical fields.

Our simulations show we can transmit 1.9 kilowatts of power while meeting federal safety guidelines,” Chabalko said. “This is equivalent to simultaneously charging 320 smart phones.”

A research report on QSCR by the Disney Research team of Matthew J. Chabalko, Mohsen Shahmohammadi and Alanson P. Sample was published in the online journal PLOS ONE.


How To Turn Sunlight, Heat and Movement Into Electricity — All at Once

Many forms of energy surround you: sunlight, the heat in your room and even your own movements. All that energy — normally wasted — can potentially help power your portable and wearable gadgets, from biometric sensors to smart watches. Now, researchers from the University of Oulu in Finland have found that a mineral with the perovskite crystal structure has the right properties to extract energy from multiple sources at the same time.

perovskite solar panel

Perovskites are a family of minerals, many of which have shown promise for harvesting one or two types of energy at a time — but not simultaneously. One family member may be good for solar cells, with the right properties for efficiently converting solar energy into electricity. Meanwhile, another is adept at harnessing energy from changes in temperature and pressure, which can arise from motion, making them so-called pyroelectric and piezoelectric materials, respectively.

Sometimes, however, just one type of energy isn’t enough. A given form of energy isn’t always available — maybe it’s cloudy or you’re in a meeting and can’t get up to move around. Other researchers have developed devices that can harness multiple forms of energy, but they require multiple materials, adding bulk to what’s supposed to be a small and portable device.

This week in Applied Physics Letters, Yang Bai and his colleagues at the University of Oulu explain their research on a specific type of perovskite called KBNNO, which may be able to harness many forms of energy. Like all perovskites, KBNNO is a ferroelectric material, filled with tiny electric dipoles analogous to tiny compass needles in a magnet. Within the next year, Bai said, he hopes to build a prototype multi-energy-harvesting device. The fabrication process is straightforward, so commercialization could come in just a few years once researchers identify the best material. “This will push the development of the Internet of Things and smart cities, where power-consuming sensors and devices can be energy sustainable,” he said.

This kind of material would likely supplement the batteries on your devices, improving energy efficiency and reducing how often you need to recharge. One day, Bai said, multi-energy harvesting may mean you won’t have to plug in your gadgets anymore. Batteries for small devices may even become obsolete.


Hand-Held Breath Monitor To Detect Flu

Perena Gouma, a professor in the Materials Science and Engineering Department at The University of Texas at Arlington, has devised a hand-held breath monitor that can detect the flu virus. The single-exhale sensing device is similar to the breathalyzers used by police officers when they suspect a driver of being under the influence of alcohol. A patient simply exhales into the device, which uses semiconductor sensors like those in a household carbon monoxide detector.  The difference is that these sensors are specific to the gas detected, yet still inexpensive, and can isolate biomarkers associated with the flu virus and indicate whether or not the patient has the flu. The device could eventually be available in drugstores so that people can be diagnosed earlier and take advantage of medicine used to treat the flu in its earliest stages. This device may help prevent flu epidemics from spreading, protecting both individuals as well as the public health.

Gouma and her team relied on existing medical literature to determine the quantities of known biomarkers present in a person’s breath when afflicted with a particular disease, then applied that knowledge to find a combination of sensors for those biomarkers that is accurate for detecting the flu. For instance, people who suffer from asthma have increased nitric oxide concentration in their breath, and acetone is a known biomarker for diabetes and metabolic processes. When combined with a nitric oxide and an ammonia sensor, Gouma found that the breath monitor may detect the flu virus, possibly as well as tests done in a doctor’s office. Gouma’s sensors are at the heart of her breath analyzer device.

breath monitor prototype

I think that technology like this is going to revolutionize personalized diagnostics. This will allow people to be proactive and catch illnesses early, and the technology can easily be used to detect other diseases, such as Ebola virus disease, simply by changing the sensors,” said Gouma, who also is the lead scientist in the Institute for Predictive Performance Measurement at the UTA Research Institute.
Before we applied nanotechnology to create this device, the only way to detect biomarkers in a person’s breath was through very expensive, highly-technical equipment in a lab, operated by skilled personnel. Now, this technology could be used by ordinary people to quickly and accurately diagnose illness.”

The findings are described  in the journal Sensors Source.

How To Convert Heat Into Electricity

The same researchers who pioneered the use of a quantum mechanical effect to convert heat into electricity have figured out how to make their technique work in a form more suitable to industry. In Nature Communications, engineers from The Ohio State University (OSU) describe how they used magnetism on a composite of nickel and platinum to amplify the voltage output 10 times or more—not in a thin film, as they had done previously, but in a thicker piece of material that more closely resembles components for future electronic devices.

Many electrical and mechanical devices, such as car engines, produce heat as a byproduct of their normal operation. It’s called “waste heat,” and its existence is required by the fundamental laws of thermodynamics, explained study co-author Stephen Boona.

devices-that-convert-heat-into-electricityOver half of the energy we use is wasted and enters the atmosphere as heat,” said Boona, a postdoctoral researcher at Ohio State. “Solid-state thermoelectrics can help us recover some of that energy. These devices have no moving parts, don’t wear out, are robust and require no maintenance. Unfortunately, to date, they are also too expensive and not quite efficient enough to warrant widespread use. We’re working to change that.”But a growing area of research called solid-state thermoelectrics aims to capture that waste heat inside specially designed materials to generate power and increase overall energy efficiency.


Swiss SmartWatch For Doctors

Intensive care doctors may soon be able to wear a smartwatch connected to the system that keeps tabs on the vital parameters of patients in the intensive care unit. If the patients’ readings – which are monitored in real time and stored on a central server – reach a dangerous level, an alert is sent directly to the doctor’s wrist via WiFi. The patient’s name and readings appear on the watch, so the doctor can react quickly and precisely. This application is the second step in a comprehensive monitoring system developed by EPFL’s Integrated Systems Laboratory (LSI). The Ecole Polytechnique Fédérale de Lausanne (EPFL) is located in Switzerland.

It began with the creation of a miniaturized microfluidic device that allows medical staff to monitor patients’ critical blood levels. The researchers embedded biosensors in it along with an array of electronics to transmit the results in real time to a tablet via Bluetooth. Seven blood levels are closely monitored: glucose, lactate, bilirubin, sodium, calcium, temperature and pH. The ability to send these readings to a portable device could make it easier to effectively monitor high-risk patients. It means that doctors can get the information they need at any time and place, and they can be alerted in an instant.


We deliberately chose a standard smartwatch so that we could see what it was capable of,” said Francesca Stradolini from EPFL. “Since we can’t send a huge amount of data to it, we use a central server that can evaluate the information and send an urgent request for a medical response to whoever is in charge of the intensive care unit.

The main advantage of this new approach, which was developed in collaboration with the Polytechnic University of Turin, is that it frees up doctors and other medical staff. They can move freely around the hospital and work on other things while keeping close tabs on their patients, thanks to the technology on their wrist.


Nanocomputer Confirms The Moore’s Law

A research team led by faculty scientist Ali Javey at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has done just that by creating a transistor with a working 1-nanometer gate. For comparison, a strand of human hair is about 50,000 nanometers thick. The development could be key to keeping alive Intel co-founder Gordon Moore’s prediction that the density of transistors on integrated circuits would double every two years, enabling the increased performance of our laptops, mobile phones, televisions, and other electronics. For more than a decade, engineers have been eyeing the finish line in the race to shrink the size of components in integrated circuits. They knew that the laws of physics had set a 5-nanometer threshold on the size of transistor gates among conventional semiconductors, about one-quarter the size of high-end 20-nanometer-gate transistors now on the market.


We made the smallest transistor reported to date,” said Javey, lead principal investigator of the Electronic Materials program in Berkeley Lab’s Materials Science Division. “The gate length is considered a defining dimension of the transistor. We demonstrated a 1-nanometer-gate transistor, showing that with the choice of proper materials, there is a lot more room to shrink our electronics.” The key was to use carbon nanotubes and molybdenum disulfide (MoS2), an engine lubricant commonly sold in auto parts shops. MoS2 is part of a family of materials with immense potential for applications in LEDs, lasers, nanoscale transistors, solar cells, and more.

The findings were published in the journal Science.


Nanocomputer: Carbon Nanotube Transistors Outperform Silicon

For decades, scientists have tried to harness the unique properties of carbon nanotubes to create high-performance electronics that are faster or consume less power — resulting in longer battery life, faster wireless communication and faster processing speeds for devices like smartphones and laptops. But a number of challenges have impeded the development of high-performance transistors made of carbon nanotubes, tiny cylinders made of carbon just one atom thick. Consequently, their performance has lagged far behind semiconductors such as silicon and gallium arsenide used in computer chips and personal electronics.

Now, for the first time, University of Wisconsin–Madison materials engineers have created carbon nanotube transistors that outperform state-of-the-art silicon transistors. Led by Michael Arnold and Padma Gopalan, UW–Madison professors of materials science and engineering, the team’s carbon nanotube transistors achieved current that’s 1.9 times higher than silicon transistors. The researchers reported their advance in a paper published in the journal Science Advances.

carbon nanotube integrated circuits

This achievement has been a dream of nanotechnology for the last 20 years,” says Arnold. “Making carbon nanotube transistors that are better than silicon transistors is a big milestone. This breakthrough in carbon nanotube transistor performance is a critical advance toward exploiting carbon nanotubes in logic, high-speed communications, and other semiconductor electronics technologies.”

This advance could pave the way for carbon nanotube transistors to replace silicon transistors and continue delivering the performance gains the computer industry relies on and that consumers demand. The new transistors are particularly promising for wireless communications technologies that require a lot of current flowing across a relatively small area.


Tiny High-Performance Solar Cells

University of Wisconsin—Madison engineers have created high-performance, micro-scale solar cells that outshine comparable devices in key performance measures. The miniature solar panels could power myriad personal deviceswearable medical sensors, smartwatches, even autofocusing contact lenses. Large, rooftop photovoltaic arrays generate electricity from charges moving vertically. The new, small cells, described today (Aug. 3, 2016) in the journal Advanced Materials Technologies, capture current from charges moving side-to-side, or laterally. And they generate significantly more energy than other sideways solar systems.

New-generation lateral solar cells promise to be the next big thing for compact devices because arranging electrodes horizontally allows engineers to sidestep a traditional solar cell fabrication process: the arduous task of perfectly aligning multiple layers of the cell’s material atop one another.

solar cells

From a fabrication point of view, it is always going to be easier to make side-by-side structures,” says Hongrui Jiang, a UW–Madison professor of electrical and computer engineering and corresponding author on the paper. “Top-down structures need to be made in multiple steps and then aligned, which is very challenging at small scales.

Lateral solar cells also offer engineers greater flexibility in materials selection.

Top-down photovoltaic cells are made up of two electrodes surrounding a semiconducting material like slices of bread around the meat in a sandwich. When light hits the top slice, charge travels through the filling to the bottom layer and creates electric current.

In the top-down arrangement, one layer needs to do two jobs: It must let in light and transmit charge. Therefore, the material for one electrode in a typical solar cell must be not only highly transparent, but also electrically conductive. And very few substances perform both tasks well.