Tag Archives: invention

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.

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.

Atmel ATmega8 – A World-Famous Microcontroller Created By Two Annoyed Students

AVR is a family of microcontrollers developed by Atmel beginning in 1996. These are modified Harvard architecture 8-bit RISC single-chip microcontrollers. The Atmel AVR core combines a rich instruction set with 32 general purpose working registers. Atmel’s ATmega8 comes from the AVR line of microcontroller and it is a gem of the modern maker movement. It is used as the heart of the first generation of the Arduino board to be widely adopted by electronics hobbyists. Countless creative projects are designed with those cheap yet powerful chips.

ATmega8 was originally developed in the early 1990s by two students at the Norwegian University of Science and TechnologyAlf-Egil Bogen, and Vegard Wollan. Microcontrollers are different from microprocessors in terms of built-in memory and I/O peripherals. They typically have their own onboard program memory and RAM, rather than relying on external chips for these resources.

When Bogen and Wollan were in university, they faced trouble in following the steep learning curve of the complex instruction sets for microprocessors. Most of the processors used in those days were CISC (Complex instruction set computer) based. They wanted to design a RISC (reduced instruction set computer) based microcontroller with an aim in mind to create something that would be easy to program and relatively powerful. Bogen explained in a YouTube video,

I found them very hard to us. The learning curve to get to use them was hard; I found the development tools crappy. And also I saw that the performance of the products was not where I wanted it to be.

Bogen
Alf-Egil Bogen – one of the creators of the AVR core

Computers, that are typically used on the day-to-day basis, use Von Neumann architecture. In this architecture, programs are loaded into the RAM first and then executed from the same. AVR uses the Harvard architecture, in which program memory and working RAM are kept separate, thus enables faster execution of instructions. The first prototype of AVR used ROM, which is not re-writeable, as the program memory. Later Atmel added easily programmable (and reprogrammable) flash memory to the processor core. The first commercial AVR chip, the AT90S8515, was released in 1996. Wollan says in a video,

instructions and stuff were things we were actually thinking of from the very beginning to make it efficient and easy to use from a high-level point of view

Wollen
Vegard Wollen – another creator of AVR