Terahertz Laser for Sensing and Imaging Outperforms Its Predecessors

Terahertz Laser is a high powered laser developed by Massachusetts Institute of Technology for chemical sensing and imaging. The Terahertz laser designed by the researchers of MIT, has three goals which includes high constant power, tight beam pattern and broad electric frequency tuning.

Terahertz Laser to be used by NASA on its 2021 mission to study our Galaxy’s origin

NASA has chosen the Terahertz laser for its 2021 mission to study more about our galaxy’s origin. With the help of a high altitude, balloon based telescope carrying photonic wire lasers, they will detect emission of gases like oxygen, nitrogen and carbon from the interstellar medium, which is the material between the galaxy’s star systems.

The Terahertz laser could also be used for skin and breast cancer imaging, detection of drugs and explosives and many other applications.

The design of the Terahertz Laser

The design of the Terahertz laser is unique which uses pairs of efficient wire lasers and sync their oscillations. On combining the output of the pairs there will be a single, high power beam with minimum beam divergence, which is the angle the beam moves away from its focus over distance. The individual paired lasers can be fine-tuned to obtain improvements in resolution and fidelity in measurements. All these give rise to less noise and higher resolution in order to achieve more cost effective and reliable chemical detection and medical imaging.

In the past, people have made a laser with high beam quality or with high continuous wave power or have done frequency tuning in lasers. But all the designs have one of the factors lacking. Ali Khalatpour, a graduate student in electrical engineering and computer science, who is also the author on the paper describing the Terahertz laser in Nature Photonics says that this is the first time where all three metrics are present in the chip-based Terahertz laser.

NASA has chosen the Terahertz laser for its 2021 mission

NASA will be using the Terahertz laser for its 2021 mission to detect gas emissions from the interstellar medium. By procuring data over a few months, they will get insight into the birth of the star and evolution. They will get more knowledge of the Milky Way and the Large Magellanic Cloud Galaxies which are close by.

NASA selected a new semiconductor based terahertz laser which is suitable for spectroscopic measurement of oxygen concentrations in terahertz radiation. It is a band of electromagnetic spectrum between microwaves and visible light.

Achieving three metrics in chip-based terahertz lasers

Researchers had developed new types of quantum cascade lasers known as photonic wire lasers. These were bidirectional and hence less powerful. This issue was sorted out by placing mirrors within the laser’s body. Since the terahertz radiation is too long, and the terahertz laser is small, it was difficult to fix it within the laser so much so most of the light travels outside the laser’s body. In the laser that NASA selected they developed a design to control how the electromagnetic wave travels along the laser and emit in one direction. They were able to obtain high efficiency and beam quality, but it did not allow for frequency tuning.

To overcome this, the researchers applied the concept of pi-bonding to the lasers, enabling close connections between the wire lasers. This coupling allowed phase locking of two or more wire lasers.
To obtain frequency tuning, they used tiny knobs to alter the current of each wire laser, which changes the refractive index. This change in refractive index together with coupled lasers, gives rise to a continuous frequency shift to the pair’s center frequency.

The researchers are building a system with a high dynamic range of more than 110 decibels which can be used for many applications including skin cancer imaging. Since skin cancer cells absorb terahertz waves more strongly than healthy cells, the terahertz lasers will be able to detect them.



With terahertz lasers having the three performance metrics, they can improve imaging capabilities and can be used in other applications.

Gelsight Sensor Giving Robots a Sense of Touch

Innovative Technology – GelSight Sensor

The research group of Ted Adelson at MIT’s Computer Science and Artificial Intelligence Laboratory – CSAIL had unveiled an innovative sensor technology known as GelSight sensor, eight years ago which utilised physical contact with an object in providing an amazing comprehensive 3-D map of its surface.

The two MIT teams have now mounted Gelsight sensors on the grippers of robotic arms providing the robots with better sensitivity and agility. Recently the researchers had presented their work in twofold paper at the International Conference on Robotics and Automation.

Adelson’s group in one paper had utilised the data from the GelSight Sensor to allow a robot to judge the hardness of surfaces it tends to touch a crucial ability if household robots are to handle the daily objects. In the other Robot Locomotion Group of Russ Tedrake at CSAIL, GelSight Sensors were used to allow a robot to manipulate smaller objects than was earlier possible.

The GelSight sensor is said to be somewhat a low-tech solution to difficult issues comprising of a block of transparent rubber. The gel of its name is one face which is covered with metallic paint. When the paint coated face is pressed against an object, it tends to adapt to the objects shape

GelSight Sensor: Easy for Computer Vision Algorithms

Due to the metallic paint the surface of the object became reflective and its geometry became much easy for computer vision algorithms to understand. Attached on the sensor opposite the paint coated surface of the rubber block one will find three coloured light with a single camera.

Adelson, the John and Dorothy Wilson Professor of Vision Science in the Department of Brain and Cognitive Sciences has explained that the system is said to have coloured light at various angles and it tends to have this reflective material and on viewing the colours, the computer is capable of figuring out the 3-D shape of what that thing would be.

A GelSight sensor in both the groups of experiments had been mounted on one side of a robotic gripper which is a device to some extent like the head of pincer though with flat gripping surfaces instead of pointed tips.

As for an autonomous robot, gauging the softness or hardness of objects is needed in deciding where and how hard to grasp them but also on how they would behave when moved, stacked or even laid on various surfaces. Moreover physical sensing would also assist robots in differentiating object which may look identical.

GelSight Sensor: Softer Objects – Flatten More

In earlier work, robot had made an effort to evaluate the hardness of object by laying them on a flat surface and gently jabbing them to see how much they give. However this is not how humans tend to gauge hardness. Instead our conclusion depends on the degrees to which the contact area from the object to our fingers seems to change as we press it.

Softer objects seem to flatten more increasing the contact area. This same approach had been utilised by the MIT researchers. A graduate student in mechanical engineering and first author on the paper from the group of Adelson, Wenzhen Yuan had utilised confectionary mould in creating 400 groups of silicon objects with 16 objects for each group.

 In each group, the object seemed to have the same shapes though with altered degrees of hardness which was measured by Yuan utilising a standard industrial scale. Then GelSight sensor was pushed against each object physically and thereafter documented on how the contact pattern seemed to change over a period of time thereby producing a short movie for each object.

In order to regulate both the data format and keep the size of the data adaptable, she had extracted five frames from each movie, consistently spaced in time describing the formation of the object which was pressed.

Changes in Contact Pattern/Hardness Movement

Eventually the data was provided to a neural network that mechanically looked for connections between changes in contact patterns and hardness movements resulting in the system taking frames of videos as inputs producing hardness scores with high accuracy.

A series of informal experiments were also conducted by Yuan wherein human subjects palpated fruits and vegetables ranking them according to their hardness. In every occasion, the GelSight sensor -equipped robot came to the same rankings.

The paper from the Robot Locomotion Group originated from the experience of the group with the Defense Advanced Research Projects Agency’s Robotics Challenge – DRC wherein academic as well as industry teams contended to progress control systems which would guide a humanoid robot through a sequence of tasks linked to theoretical emergency.

 An autonomous robot usually tends to utilise some types of computer vision system in guiding its operation of objects in its setting. Such schemes tend to offer reliable information regarding the location of the object till the robot picks the object up.

GelSight Sensor Live-Updating/Accurate Valuation

Should the object be small most of it will be obstructed by the gripper of the robot making location valuation quite difficult. Consequently at precisely the point where the robot needs to know the exact location of the object, its valuation tends to be unreliable.

 This had been the issue faced by the MIT team at the time of the DRC when their robot had picked up and turned on a power drill. Greg Izat, a graduate student in electrical engineering and computer science and first author on the new paper had commented that one can see in the video for DRC that they had spent two or three minutes turning on the drill.

 It would have been much better if they had a live-updating, accurate valuation of where that drill had been and where their hands were relative to it. This was the reason why the Robot Locomotion Group had turned to GelSight. Izatt together with his co-authors Tedrake, the Toyota Professor of Electrical Engineering and Computer Science, Aeronautics and Astronautics and Mechanical Engineering, Adelson together with Geronimo Mirano, another graduate student in the group of Tedrake had designed control algorithms which tends to utilise computer vision system in guiding the gripper of the robot towards a tool and thereafter turn location estimation over to a GelSight sensor when the robot is said to have the tool in hand.

Mapping the Effects of Crystal Defects

A crystal seems to be flawless because almost all the cells have perfect configuration of molecules or atoms. Every cell is also positioned in a 3D space without any distortion. Many cells have more than one atom. However, when there is any imperfection, it is considered as crystal defects.

Dislocation types in a crystal-

Dislocation is one of the common defects that you may see in many crystals. It is such as aspect, where atoms do not remain in proper place in a structure of crystal. In fact, dislocation may be caused due to the application of stress.Dislocations can be of two types- screw and edge defects. Some of the defects are also a combination of these two extreme levels of dislocation. These imperfections have considerable impact on the phonons and on the crystals’ electrical features. Edge dislocation may be observed very easily. Locus for imperfect points in any lattice is placed next to the line. The bonds of atoms are highly distorted.

Screw defect is little harder to be identified. Its motion is caused because of some stress. However, movement of the line is vertical to the displacement of atoms. Some atoms do not get shifted from actual place, while others are transferred to a new site. Many other atoms may also be engaged in the moving process. Just a part of bonds gets separated at particular time. This kind of movement does not need much amount of force.

Data collected by studying about dislocations-

Some experts at MIT have discovered significant data on the working of all interactions. Such efforts may be helpful to create thermoelectric tools and many other advanced electronic structures. All the details from research have been issued in a journal (named as Nano Letters). Li, who is associated with the journal, has considered dislocation as a kind of atomic defects in standard crystal.

How to know about crystal dislocation-

In fact, there’re two different techniques, which are useful to clarify the dislocation or defect of phonon. With the explanation of Li, some queries have been solved. MIT members have detected a fresh statistical process in order to evaluate the systems. With the use of quasi particle, these experts have created dislon in order to have a clarification of all the mysteries.

The latest theory may start differently because this mainly depends on thorough quantum theory. Perhaps, it settles many issues, which cause a dispute on static and dynamic scattering system. It has been seen that these are two acute cases in a same framework.

Li as well as his associates have led to some progress as they have dealt with the facts about the field of dislocation strain. A professor of Missouri University has said that dislocation may lead an intense impact on composition of any material. However, the field of strain with longer range may prevent any direct measurement of the effects of dislocation. Quantization, related to a research paper, can solve the problems, and such approach may also develop the perception of the results from dislocations.

MIT Media Lab Disobediance Prize Worth $25000

How Breaking the Rules Could Win You $250,000

The M.I.T. Media Lab has thrown everyone I a frenzy by laying down a proposition which is as simple as it can get. It is offering prize money worth $250,000 inch to those who are willing to go ahead, break the rules or indulge in shaking up the status quo. There are literally no rules attached to this offering and certainly it isn’t a joke purported by some people rather M.I.T. Media Lab has opened the nomination for its new Disobedience Award for all. In short it can be said this lab is aiming at congratulating the people for their courage to remove the shackles of the society or institution which results in bringing good in the society.

The reason behind launching this award

It has been said that there are huge number of people who actively doing really important things for the betterment of the society which usually results from either breaking the rules or simply sticking to their beliefs. Those people know that they will be punished for this but yet they move forward without fear of repercussions and punishment. Our world is filled with such exceptional people but most of them go unnoticed or endure hardships on their own without any financial help. This award will help in recognizing such individuals or groups who gives us courage just like Malala and others.

M.I.T lab further points out they had found out that in most of the large institutions there are basically two ways of making progress. It is either by following the rules and working as per the stated process or in some extreme cases taking radical approach which does away with the process and rules and helps in opening a new road towards success. Apple not giving a backdoor to the government agencies can be taken as a prime example of doing something away from the rules even knowing that it can lead to punishment.

All you need to know about the MIT Award 

M.I.T has not suddenly launched this prize money for an award out of the blue rather than had announced it last year but the nomination process has been established just now. The prize money in cash is being funded by the Reif Hoffman who is popularly known as the co-founder of the largest professional website called LinkedIn. The entries for this award will be reviewed by a panel of judges comprising of scientists, activists, engineers and designers. All the living individuals and eligible to participate in this award and the submissions are open from this week and it will end on May 1. The recipient of this prestigious and ambitious award will be announced by the M.I.T on July 21.

As stated earlier this award created a certain level of excitement among the people. The Executive director of the Albert Einstein Institution named Jamila Raquib has stated that she would like to someone gets benefitted by the prize. She further elaborates that kind of award will help in bringing varied kind of structures, knowledge and resources to the individual or group which is not easy to get in this age.

For Nomination Follow.

Engineers Harness Stomach Acid to Power Tiny Sensors

Since the period of ancient civilization to the contemporary world; the health sector is having a place in the center of the developments, as this is attached to the human race and their well-being. The scientific and technological advancements also paved the way for some of the major discoveries or inventions in the medical science and its allied departments, which are collectively helping us in countering the attack of various ailments.

While the research and development are going on in the different segment of the medical science, at the same time, some of the major breakthroughs have taken place in the health engineering sector, which is having real importance in the treatment of some of the major diseases.

Researchers at the MIT, Women's Hospital and Brigham have together designed and developed a tiny voltaic cell, which can be sustained by the most destructive acidic fluids inside the stomach. This system is able to generate sufficient power, which can be helpful in running small sensors and drug delivery devices and able to resides inside the gastrointestinal channel for a longer period of time.

Issues to be Noted

Although there are other batteries, but this kind of power is having the potential of offering safer and cheapest possible alternative to the existing batteries, which are now being in use to power such kinds of devices, claimed by the researchers. It is often found that traditional power batteries get damaged due to intestinal acidic fluids and the respective device failed to operate according to the need, which causes lots of problems for the person concerned.

Now the answer to this problem is being designed by the scientists in the form of these voltaic cells, which is able to save itself from any kind of vulnerable fluid attacks. Two eminent researchers in this field; Giovanni Traverso, the research affiliate engaged in the prestigious Koch Institute for Integrative Cancer Research and Robert Langer, the David H. Koch Institute Professor at the MIT, have designed, built and tested some of the major devices in past, which can be of great help in sensing physiological conditions like heart rate, temperature, breathing rate and more importantly to deliver drugs, with an intention to treat the specific diseases.

Conclusion

On the basis of research and inferences, made by the researchers, this unique development of the device can be of great influence on the search of the new generation electronic ingestible tablets, which will enable magical means that could monitor the basic health of the patient or in treating the diseases.

While there are possible risks in the traditional batterie; these new small voltaic cells are having the potential that can overcome the problem of getting destructed by intestinal fluids thus help the medical devices, planted inside the human body, mentioned by the specialists in this field.

 It can be noted that the study team took the inspiration of this invention from a simple variation of the voltaic cell, popularly known as the lemon battery, which is having two electrodes, with a copper penny and the galvanized nail - that stuck in lemon.

Movable Micro Platform Floats on a Sea of Droplets

The popularity of small consumer electronics and ever growing rise of their shipments has brought the need of bringing ever-evolving advancement in the technologies. The production of electronic chips and other devices rely on the microelectronic mechanical systems or commonly referred as MEMs which are essentially are tiny machines which help in enhancing the abilities of those electronic devices.

A team of researchers at MIT had come up with an innovative way of ensuring that the movable part of the machine doesn’t get in touch with each other. This will ensure the major source of wear, tear and eventually failing of the electronic device. In this new invention a layer of liquid droplets were used to support a tiny yet movable platform which helps floating the droplets at top of it.

The movement of the platform can easily be controlled effectively and it can also be utilized to alter the dimensions of the droplets by raising, lowering as well as tilting the platform. Their finding has been published in Applied Physics Letters and it has been coauthored by MIT team which includes Daniel Preston along with six others.

How this new system works? 

In this system the droplets way of interacting with the below them is altered as per the need of the hour and it is governed by a scientific a characteristic which is called contact angle. The contact angle specifically helps in measuring how steep the edge of the droplet when it meets with the surface. The usage of droplets will help in tuning across a whole range of the device by applying variable voltage to the surface.

The research team behind this invention is filled with graduate students from MIT namely Ariel Anders and Yangying Zhu and an undergraduate student by the name DingRan Dai. Their work was extensively supported by the Office of Naval Research and the National Science Foundation.

How this droplet platform was created? 

Researchers came with a smart solution to maintain the position of droplets by allowing them to slide around through the treating the underside of the floating platform. Researchers have created the floating surface with small circles of hydrophilic material. But researchers have been able to get the droplets in their place by securely pinning it to the water attracting surface. This ultimately helps in keeping the platform securely.
During the initial testing of this device researchers found that they were able to keep the droplets in the vertical positioning up to the level of 10 microns.

The future application of the droplets

In practical this approach will help in offering simple and cost effective solution to the manufacturers which is great benefit over the existing techniques present in the industry. One of the assistant professors at Centre for Nano Science and Engineering present the Indian Institute of Science named Prosenjit Sen has further elaborated the best thing offered by the droplets is that it offers a degree of vibration isolation which is sorely missed in the solid stages.

Meet Luigi MIT's Sewer Scouring Robot

Luigi – Sewer Trawling Robot

A sewer-trawling robot has been created by Underworlds, a project from Senseable City Lab of MIT which has been designed in connecting the gold mine of information prowling in the sewer.The robot in question is known as Luigi and up to now, has been deployed underground in Cambridge, Massachusetts; Boston and Kuwait as a part of an experimental program which could be spun out in various cities worldwide.

Scientists are of the belief that on researching fecal matter they would be capable of envisaging the spread of infectious diseases, provide an image of the collective health of the community together with influence policy. The Underground project, launched in 2015, has been bringing experts together from engineering, public health and biology sectors.

Carol Ratti, MIT professor, co-principal investigator and founder of Senseable City Lab had commented that `the name (Underworlds) tends to highlight the rich amount of insights hidden in our cities and in this case in sewage’. Scientists can monitor urban health patterns and diabetes, analyse drug usage as well as identify antibiotic-resistant bacteria, by sampling and interpreting human waste.

Biomarkers in Human Waste – Insight in Infectious Diseases

Co-principal investigator of Underworlds and director of the Alm Lab, Eric Alm had explained that ` we all tend to flush valuable health data in the toilet. Sewers tend to signify an exceptional opportunity where health data from everyone in a community is assembled together.

With the provision of biomarkers in human waste, they are in a position of obtaining some insight regarding infectious diseases like flu strains, which has ultimately made it possible for the scientists to expect and alleviate epidemics. Collection of fecal samples is not really a desirable task.

 Ratti recalls that initially the sampling method had been very `low-tech’ and the same was lowered to a 20-foot pole with a bottle taped to the end of it in a manhole and the sample had been scooped out. Sampling waste by hand was not enjoyable and hence they started developing the robots.

To quicken things up, the team had installed a large pump at street level. He commented that all these methods seemed to be quite messy. It was then that the first automated sewage-scouring robot, Mario had come to the rescue.

Nintendo – First Generation Model

Named after the famous plumber, Nintendo, the first generation model updated the process though was not adequately fast. Then came in Luigi, which has been much more compact and economical wherein the new model has enabled the team to streamline the collection process.

Luigi measuring around 3feet long and 3 inches in diameter comes with a motor, pump together with a filter. In order to get the task done, the remote-controlled robot tends to descend from street level to the waste water and seizes the bacteria by pumping the water through a filtration system.

 On obtaining the samples Luigi tends to return to street level for refining and dispensation. Ratti has stated that usually the examination of sewage is carried out in the treatment plants beyond the cities which tend to lose the precise data owing to the time in transport.

However they are capable of beginning the filtration process of fecal and urinary matter in situ. Moreover accumulating fresh sample seems to be critical since gut bacteria tend to die off as soon as they enter the sewer system.

MIT's new Chronos System Promises Precise Wi-Fi Tracking

Chronos – Wireless Localization Technology

Several users tend to use Wi-Fi to browse social media, check emails and watch videos. However according to Dan Misener, Radio technology columnist, researchers at MIT have invented something known as Chronos which is the latest way of using Wi-Fi in tracking the exact position down to the centimetre. Chronos is a `wireless localization’ technology or a Wi-Fi positioning system and is essentially a method of utilising Wi-Fi in figuring out where you are.

There are various means of doing this though Chronos tends to work by measuring the time it may take for a signal to travel from one wireless device to another device. For instance, if you have a smartphone and it is connected to a wireless router, the router tends to send information to the phone. The phone receives the same and then sends back a signal.

On measuring the time taken and by applying some calculation to the signal, one can determine where the smartphone is with regards to the router, the distance and the angle. In many ways, it tends to be the same way how radar or sonar systems seem to work. Chronos could be considered as a way to turn a regular Wi-Fi router into a kind of radar system which can distinguish objects and where they could be in the world.

Difference is Accuracy

The big difference is the accuracy. Customers-grade GPS tend to pinpoint you within a few metres distance but Chronos system tends to locate you within tens of centimetres. Moreover there are instances where GPS sometimes does not function at all like in underground or when one is indoors. Chronos tends to work anywhere within a Wi-Fi router range.

There are various other Wi-Fi based location system and are often utilised in airports, hotels and shopping mall to track foot traffic. U.S. malls tend to use shopper’s cell phones to track them, but those systems need several access point and many routers to cover a large area and triangulate the location of someone.

The distinctive thing regarding Chronos is that it only needs a single access point, a single router and one can set this up at home or a small business without incurring much expense.

Utilised in Locating Lost Device within the Home

The researchers have also informed that Chronos tends to be 20 times more accurate than the prevailing systems. One reason for using it in home is `home automation’ wherein there is a rise of the smart homes which tends to respond to who is in them.

Hence knowing who is at home and where people are within a home could be useful information. In a demonstration, the researchers had shown how Chronos tends to accurately identify which room a person was in 94% of the time. This device could also be utilised in locating a lost device within the home which could be helpful whenever a phone or a tablet would be misplaced.

Chronos can be used in controlling who gets to access the Wi-Fi, which could be useful for small businesses. Deepak Vasisht, one of the MIT researchers had informed at last month’s symposium, that if one walks into a Starbucks, they tend to get free Wi-Fi, but if one talks to them, they inform that they are very much keen in restricting free Wi-Fi access only to their customers and do not want to give free Wi-Fi to their neighbours which could end up causing congestion for their own customers. Hence a coffee shop could use Chronos to cut off Wi-Fi freeloaders.