Technology category

A new type of transistor (a) harnesses a property called negative capacitance.

Researchers Demonstrate New More Efficient FET By Implementing Negative Capacitance

A group of Researchers from Purdue University in Lafayette, Indiana demonstrated the effect called negative capacitance by making a new type of more energy efficient transistor. This new kind of Field Effect Transistor (FET) proves a theory introduced in 2008 by Supriyo Datta, the Thomas Duncan Distinguished Professor of Electrical and Computer Engineering, and Sayeef Salahuddin, who is a professor of Electrical Engineering and Computer Sciences at the University of California, Berkeley.

A new type of transistor (a) harnesses a property called negative capacitance.
A new type of field effect transistor harnesses a property called negative capacitance.

The researchers from Purdue University made a much thinner layer using the semiconductor Molybdenum disulfide. It creates a channel adjacent to an important part of transistors called the gate. By using a “ferroelectric material” called hafnium zirconium oxide, they created a negative capacitor which is a key component in the newly designed gate.

Capacitance is the property of any dielectric or conductor to store electrical charge. It is ordinarily a positive quantity. With the help of ferroelectric materials, the new FET gate structure allows a negative capacitance. Due to this the energy needed to switch the FET is considerably reduced. This new design just substitutes hafnium oxide with hafnium zirconium oxide. Hafnium oxide is a conventional material to use in modern FETs as a dielectric material to isolate the gate. This work is led by Peide Ye, Richard J. and Mary Jo Schwartz of Purdue University.  Ye said,

The overarching goal is to make more efficient transistors that consume less power, especially for power-constrained applications such as mobile phones, distributed sensors, and emerging components for the internet of things

Transistors act like a tiny electronic switch. They can turn on and off very fast, allowing computers to process information in binary code. A proper switching off state is very important to ensure that no electricity “leaks” through. This switching normally needs a minimum of 60 millivolts for every tenfold increase in current. This requirement called the thermionic limit. However, transistors using negative capacitance can break this fundamental limit, because they can switch at far lower voltages resulting in smaller power consumption.

New findings from the research group have advanced the conventional transistor technology to a much efficient and faster level. Only time will justify if the new ‘negative capacitance‘ FETs can revolutionize the modern electronics.

Flexible Graphene sensor by Chalmers University

Researchers Develop Transparent Flexible Terahertz Sensors With Graphene

The researchers of the Swedish Chalmers University of Technology have developed a new design of terahertz sensor using Graphene. This flexible sensor can be integrated into wearable materials. Most importantly, it can be manufactured very cheaply and also it is practically transparent. This new type of sensor could be a major breakthrough by opening doors of many new applications.

Flexible Graphene sensor by Chalmers University
Flexible Graphene sensor by Chalmers University

The terahertz frequency band ranges from 100 to 10,000 GHz. Terahertz radiation is able to penetrate materials that block visible and mid-infrared light. This technology opened up a range of potential applications in medical diagnostics, process control, and even intelligent vehicles. Jan Stake, the head of the Terahertz and Millimetre Wave Laboratory at Chalmers, said,

Terahertz graphene-based FET detectors have been demonstrated on rigid substrates such as SiO2/Silicon, and flexible devices such as graphene and other concepts have been demonstrated at RF/microwave frequencies.

This band is also used by the so-called “nude-scanners” used at airport check-in desks to look for illegal items carried by passengers. THz waves penetrate normal clothing hence it can detect weapons made of plastic. As Non-metallic weapons cannot be detected by ordinary metal detectors used at the entry gates and by hand-held scanners. Thus these new inexpensive sensors can enhance security for everyone.

Terahertz transmissions have enormous bandwidth available. THz signals can be used as carriers for high-speed information links over short distances allowing data speeds up to 100 Gb/s. On the other hand, THz waves allow uninterrupted visibility in fog or rain for motorized vehicles.

There are many medical applications of the technology using sensors that are cheap to produce and are physically small. One important example is in the field of dermatology. Skin regions affected by cancer have a different reflective index to THz waves which makes the sensor a useful diagnostic tool.

Although being under development for a long time, conventional THz sensors were always large and expensive. With this new design, the Swedish research team has enabled the tech world with mass production of the sensors. New sensors will be small, flexible and cost-effective. Development of the sensors was funded by the European Union under the Graphene Flagship Initiative.

What the Chalmers team has done to combine flexibility and terahertz detection could also make it possible to build an Internet of Things connected via high-bandwidth 5G technologies.

Micro-spectrometer Sensor Will Let You Check Air Quality Or Blood Sugar – Using Smartphone

Now you can use your smartphone to check how clean the air is, measure the freshness of food or even the level of your blood sugar. This has never been so easy. All credit goes to the new spectrometer sensor which is developed at the Eindhoven University of Technology and can be easily attached to a mobile phone. The little sensor is just as precise as the normal tabletop models used in scientific labs. The researchers published their invention on 20th December in the popular journal Nature Communications.

The blue perforated slab is the upper membrane, with the photonic crystal cavity in the middle
Spectrometer sensor construction: The blue perforated slab is the upper membrane, with the photonic crystal cavity in the middle

Spectrometry is the analysis of the light spectrum. It has an enormous range of applications. Every organic and inorganic substance has its own unique ‘footprint‘ in terms of light absorption and reflection. Thus it can be recognized by spectrometry. But precise spectrometers are bulky and costly since they split up the light into different colors (frequencies), which are then measured separately.

The intelligent sensor developed by Eindhoven researchers is able to make such accurate measurements in an entirely different way. It uses a special photonic crystal cavity that acts as a ‘trap’ of just a few micrometers into which the light falls and cannot escape. This trap is situated in a membrane. In the membrane, the captured light generates a tiny electrical current which can be measured accurately. The accurate working cavity design is made by Žarko Zobenica, a doctoral candidate.

The sensor can measure only a narrow range of light frequencies. To increase the frequency range, the researchers placed two of these membranes above each other closely. The two membranes affect each other. Changing the separation gap between them by a tiny amount also changes the light frequency that the sensor recognizes. To understand this the researchers, supervised by professor Andrea Fiore and associate professor Rob van der Heijden, included a MEMS or micro-electromechanical system.

This mechanism can change the measured frequency by changing the separation between the membranes. In this way, the sensor is able to cover a range of about thirty nanometers. Within which the spectrometer can recognize some hundred thousand frequencies with an exceptional precision. The research team demonstrated several applications like an extremely precise motion sensor and a gas sensor. All made possible by the clever use of the tiny membranes.

As per Professor Fiore‘s expectations, it will take another five years or more before the new spectrometer actually gets into a Smartphone. The main difficulty at this moment is the frequency range covered is still too small. It covers only a few percent of the most common spectrum, the near-infrared.

Given the huge potential and the wide field of applications, micro-spectrometers can become just as important as the camera in the smartphones of future.

Flexible PCB designed by the researchers

Researchers Develop New Technique To Print Flexible Self-healing Circuits For Wearable Devices

The researchers of North Carolina State University in the US, lead by Jingyan Dong, have developed a new technique for directly printing flexible, stretchable metal circuits. The innovative technique can be used with multiple metals and alloys. It is also compatible with existing manufacturing systems which can integrate this new printing technology effortlessly.

Flexible PCB designed by the researchers
Flexible PCB designed by the researchers

The technique uses the well known electrohydrodynamic printing technology. This popular technology is already used in many manufacturing processes that use functional inks. But instead of using conventional functional ink, Jingyan Dong’s team uses molten alloys having melting point as low as 60 degrees Celsius. This new technique was demonstrated using three different alloys, printing on different substrates such as glass, paper, and two types of stretchable polymers. Jingyan Dong added,

Our approach should reduce cost and offer an efficient means of producing circuits with high resolution, making them viable for integrating into commercial devices.

The researchers tested the flexibility of the circuits on a polymer substrate and found that the circuit’s conductivity was uninterrupted even after being flexed 1,000 times. The circuits were still electrically firm even when stretched to 70 percent of tensile strain. The above figures are surprising enough, especially when printing flexible wearables is the main target.

Even more interesting, the circuits can heal themselves if they are broken by being bent or stretched beyond their limitations. On the other hand, because of the low melting point, one can simply heat the affected area up to around 70 degrees Celsius and make the metal flow back together, repairing the related damage with ease.

The researchers demonstrated the functionality of the printing technique by creating a high-density touch sensor, packing a 400-pixel assemblage into one square centimeter. The researchers have demonstrated the flexibility and functionality of their approach. Now, they are planning to work with the industry sector to implement the technique in manufacturing wearable sensors or other electronic devices.

The days of truly flexible, self-healing wearable smart gadgets are not so far because of the hard work of these researchers.

Transistors- The 70-year-old invention that changed the world

First transistor made in 1947- Point contact transistor

Its been 70 years since the fundamental building block of electronics was created, and it has been getting smaller, and better since then. The invention that won the Nobel prize for John Bardeen, Walter Brattain, and William Shockley in 1956 revolutionized electronics and made it into the IEEE milestone list. Before 1947 computers used vacuum tubes, which could be several inches long, consumed massive amounts of power, and needed to be regularly replaced. Nowadays, billions of transistors can fit in the area of a single vacuum tube, can last for many years and are a lot more efficient.

What is a transistor? For computing, basic binary logic operations are needed in order to perform calculations, so the objective of both vacuum tubes and transistors was to toggle the device between on and off position (1 or 0). A transistor is made from semiconductor material (usually silicon or germanium) capable of carrying current and regulating its flow. The semiconductor is doped which results in a material that either has extra electrons (n type) or has holes in the crystal structure (p type), and the transistor is made from a combination (layers) of both of these types. When current is applied, electrons can go through the different layers allowing energy to flow. Transistors can work as a switch or an amplifier depending on how it’s configured.

In 1965, the intel co-founder formulated Moore´s Law which states that every 2 years the number of transistors in a dense integrated circuit doubles. Since then Gordon E. Moore has been right, but soon the law will no longer be true which will lead to either a slowdown in technologic advancement or a new golden era for engineering where a new technology will replace transistors and a race to make it better and more efficient will again begin.

Transistors have powered 70 years of advances in computing, and it all started with the point contact transistor made by three scientists who changed history. However, other ways must be found to make computer more capable, but the problem is not just making smaller transistors, but also about the time it takes for information to get from one side to another. Transistors can be found in cellphones, computers, cameras, electronic games, and pretty much anything electronic that performs calculations, so if transistors stop advancing so will all these devices. Perhaps, consumers won’t feel the impact right away, but scientists in need of fast processing and super computers will.

[source]

Brand New BiCMOS Flexible Transistor

 

The transistor revolutionized the field of electronics, and paved the way for smaller and cheaper radios, calculators, and computers, among other things since its very first practically implemented device as a point-contact-transistor invented in 1947 and getting the Nobel Prize in Physics in 1956.

Now, engineers from the University of Wisconsin-Madison (UW-Madison) have built the most flexible, fully-functional transistor in the world!  The BiCMOS  (Bipolar Complementary Metal Oxide Semiconductor) thin-film transistor has all current transistor’s characteristics: speed, carrying large current and low dissipation – but it is extremely flexible.

This is an interesting advance that could open the door to an increasingly interconnected world, enabling manufacturers to add smart wireless capabilities to any number of large or small products that curve, bend, stretch and move.

Making traditional BiCMOS flexible electronics was difficult, in part because the process takes several months and requires a multitude of delicate, high-temperature steps. Even a minor variation in temperature at any point could ruin all of the previous steps. This fabrication process is not currently as commercially viable for most of applications.

However, the engineers fabricated their flexible electronics on a single-crystal silicon nanomembrane on a single bendable piece of plastic. The secret to their success is their unique process, which eliminates many steps and slashes both the time and cost of fabricating the transistors.

This new electronic has the potential to change the electronic’s industry in a new way. Everything touched by electronics (computers, microcontrollers, sensors…) could be completely flexible due the easily of this new technology to scale up to commercial levels.

The vast majority of transistors are now produced in integrated circuits. A logic gate consists of up to about twenty transistors whereas an advanced microprocessor, as of 2009 and with a cost of just a couple of usd, can use as many as 3 billion transistors. This is the best transistor’s advantage: mass-production with a extremely low cost.

For that reason, the transistor is the key active component in practically all modern electronics. The transistor is on the list of IEEE milestones and many consider it to be one of the greatest inventions of the 20th century.

This new flexible transistor could be in future electronic boards for a flexible electronics development and applications never even seen before. Definitely, the future is now.

The “Neuropixels” probe records brain signals

 

After $5.5 millions collaboration and a lot of work during the past four years of engineers at Imec, the next-generation electrodes called Neuropixels probe were designed to record hundreds of neurons in the brain. Imec is an international nano electronics research center dedicated to build and test powerful new devices for detecting neural activity within the brain.

To understand how the brain operates, we must measure the joint activity of a myriad individual neurons distributed across brain regions. Until recently, this has been impossible.

Their success is due to three innovations:

  1. a multiplayer fabrication process that allows 384 interconnects on a thin shank;
  2. on-shank CMOS circuitry that allows 384 sites to be rapidly selected from a total of 966;
  3. on-device processing that amplifies, digitizes, and multiplexes the signals.

Neuropixels thus constitute a self-contained recording system: the data that emerge are already digital, and can be read by a simple, inexpensive interface to a standard computer.

Probe Options

There are four probe options, all four have the same on-probe amplification and digitization, and can all be used interchangeably with the same headstages and recording equipment.

  • Option1 probes (no switches, no amps) have 5mm-long shanks, and have no switches (they can only record from the most distal 384 sites) or on-site buffer amplifiers.
  • Option2 probes (no switches, yes amps) have 5mm-long shanks, and have no switches
  • Option3 probes (yes switches, no amps) have 10mm-long shanks with 960 total sites accessible via switches; they do not have on-site buffer amplifiers.
  • Option4 probes (yes switches, yes amps) have 10mm-long shanks with 966 total sites accessible via switches; they have on-site buffer amplifiers. Option4 probes can only record 276 channels at a time.

In practical terms, the probes with buffer amps (2 & 4) have slightly higher RMS noise levels in saline (~10-12µV RMS compared to 6-9) but may have superior rejection of certain types of noise.

Switched probes (3 & 4) do not seem to have any deficits relative to the un-switched, unless the shorter shank of the unswitched probes is more suitable for your experimental situation.

Basic Probe Details

  • Neuropixels probes have 384 recording channels (i.e. can record 384 signals simultaneously), and up to 966 recording sites (depending on the option)
  • Recording sites are laid out in a checkerboard pattern, see geometry note below.
  • 10 sites per group of 384 are reserved for selection as internal reference sites and cannot be used for recording (whether they are used for referencing or not)
  • Recording sites have ~200k-ohm impedances
  • Shanks are 70µm wide and 20µm thick (for Option1, shank is 50µm wide)
  • Probe weighs 0.3g, headstage weighs 1.1g.

Neuropixels probes represent a significant advance in measurement technology and will allow for the most precise understanding yet of how large networks of nerve cells coordinate to give rise to behavior and cognition.

Preliminary data examples and a user guide are available.

Solar supercapacitor creates electricity and hydrogen fuel on the cheap

A replica of the UCLA device, which can produce both electricity and hydrogen

Researchers in University of California, Los Angeles (UCLA) made a device that may help bring hydrogen powered vehicles to the masses. This device uses sunlight to produce both hydrogen and electricity at the same time. The UCLA device is a hybrid unit that combines a supercapacitor with a hydrogen fuel cell, and runs on solar power. [via]

People need fuel to run their vehicles and electricity to run their devices,” says Richard Kaner, senior author of the study. “Now you can make both fuel and electricity with a single device.

Along with the usual positive and negative electrodes, the device has a third electrode that can either store energy electrically or use it to split water into its constituent hydrogen and oxygen atoms – a process called water electrolysis.

Volterman, Your Personal Smart Wallet

With the rapid growth of technology, smartphones and e-payments are replacing cards, cash, and wallets. However, developers are still trying to keep wallets relevant in the 21st century, and Volterman is the newest attempts. Besides WiFi hotspot and power bank, Volterman also provides novel security features to protect your phone and wallet from loss.

Similar to other smart wallets, Volterman has a GPS tracking capability, so you can find it easily in case it lost. Through Bluetooth connectivity, it connects to the smartphone to ensure that you will not forget one of them. An alarm will start ringing to notify you and pick up what you have missed.

The new innovative idea on Volterman is a small built-in camera. It captures everyone trying to open the wallet while “lost mode” is running. The pictures are sent directly to the paired smartphone, meaning that you will know who is using your wallet and where is he. With an embedded SIM card, you are also able to track your wallet via the website.

Volterman’s Embedded System Specification

Inside the wallet, there is a full computing system to do all the stuff. The main components are:

  • CPU: ARM Cortex A9
  • Memory: 512MB RAM, and 32GB ROM
  • SD card: 64GB embedded card
  • Bluetooth: 5.0
  • Camera: 4MP
  • Mobile Network: Worldwide 2G, 3G
  • Wi-Fi: 802.11 BGN, Hotspot
  • GPS: A-GPS, GLONASS
  • Connector: magnetic connecter by Volterman
  • Power Bank: 2000mA, 2600mA, 5000mA, in addition to the capability of wireless charging.
  • Input voltage: 5V, 1A
  • Output voltage: 5V, 500mA

An interesting point is that the purchase price is covering the data charges for the GPS tracking and sending of photos to the Volterman server. According to the makers, Volterman will automatically connect to local networks in 98 countries, but at the moment the exact tariffs from country to country are unclear. However, it is offering up to 3 times cheaper internet cost than the regular price, with an early estimate of around $15 per 1 GB.

The Volterman comes in three different sizes: a small cardholder model $98 with 2,000-mAh power bank, a conventional bifold wallet $135 with 2,600-mAh power bank, or a larger travel size $157 designed to hold more cards, a passport and with a 5,000-mAh power bank.

After reaching more than one million dollars on IndieGoGo, Volterman is now ready for mass production and estimated to start shipping and the first quarter of 2018.

Take a look at the crowdfunding campaign video below:

ICECool – An Intra-Chip Cooling System That Is More Efficient

In the Moore’s Law race to keep improving computer performance, the IT industry has turned upward, stacking chips like nano-sized 3D skyscrapers. But those stacks have their limits, due to overheating. Researchers from IBM have solved this problem by developing an intra-chip cooling system as a contribution to ICECool program research project by the DARPA (Defense Advanced Research Projects Agency).

ICECool - intra-chip cooling system by IBM
ICECool – intra-chip cooling system by IBM

Today, chips are typically cooled by fans which blow air through heatsinks that sit on top of the chips to carry away excess heat. Advanced water-cooling approaches, which are more effective than air-cooling approaches, replace the heatsink with a cold plate that is fixed on the top of the chip.  But this approach requires extra protection and proper insulation of the chip because of the electrical conductivity of water. Neither of these technologies can cool down the chip much efficiently. Here comes the ICECool that cools the chip down from the inside rather than just from the upper surface.

ICECool uses a nonconductive fluid to bring the fluid into the chip. This completely eliminates the need for a barrier between the chip and fluid. It not only delivers a lower device junction temperature, but also reduces system size, weight, and power consumption significantly. The tests performed on the IBM Power 7+ chips demonstrated junction temperature reduction by 25ᵒ C, and chip power usage reduction by 7 percent compared to traditional air cooling. This is clearly a great achievement when the operating cost is much smaller than the conventional cooling technologies.

IBM’s ICECool intra-chip cooling system solves the problem of cooling the 3D “skyscraper” chips by pumping a heat-extracting dielectric fluid right into microscopic gaps, some no thicker than a single strand of hair, between the chips at any level of the stack. Being nonconducting, the dielectric fluid used in ICECool can come into contact with electrical connections without causing any short circuit, so is not limited to one part of a chip or stack. Based on the tests with IBM Power Systems, ICECool technology could reduce the cooling energy for a traditional air-cooled data center by more than 90 percent.