#Drive-by heat mapping In 2007, Google unleashed a fleet of cars with roof-mounted cameras to provide street-level images of roads around the world.
Now MIT spinout Essess is bringing similar rive-byinnovations to energy efficiency in homes and businesses.
The startup deploys cars with thermal-imaging rooftop rigs that create heat maps of thousands of homes and buildings per hour, detecting fixable leaks in uilding envelopeswindows, doors, walls,
and foundations to help owners curb energy loss. About the size of a large backpack, Essessrig includes several long-wave infrared radiometric cameras and near-infrared cameras.
while a Lidar system captures 3-D images to discern building facades from the physical environment.
An onboard control system has software to track the route and manage the cameras. On the software side, computer vision and machine-learning algorithms stitch together the images, extract features,
and filter out background objects. In one night, the cars can generate more than 3 terabytes of data,
which is downloaded to an onboard system and processed at the startup Boston headquarters. Combining those heat maps with novel analytics, Essess shows utilities companies
which households leak the most energy and, among those, which owners are most likely to make fixes,
along with information on the fixes that could offer the most return on investment. But the startup also works with the U s. Department of defense to help identify energy-wasting buildings on their bases.
And schools, municipalities, oil refineries, and other organizations have hired Essess to scan their facilities and find, for instance, fixes that might affect their heating bills in the winter,
says Essess cofounder Sanjay Sarma, the Fred Fort Flowers and Daniel Fort Flowers Professor in Mechanical engineering,
since more than 4 million homes and buildings in cities across the United states for military, commercial,
Revving up Essess Traditional energy audits usually involve sending one employee to a home to manually scan and record leaks.
the idea for thermal-imaging cars came to Sarma in 2009, when a company sent an employee to his home with a handheld thermal-imaging device
which took longer than expected. remember thinking, ouldn it be easier to just throw it on a car and drive by the house??
Sarma says. But there were many challenges. ery expensive thermal cameras had lower resolution than your smartphone camera,
Sarma says. Such cameras cost about $40, 000 at the time. Then, in 2011, Field Intelligence Lab student Long Phan Phd 2 made key innovations to the rig that allowed low-cost cameras (about $1,
000) to produce high-resolution thermal images. Among other things, this included an algorithm called Kinetic Super Resolution co-invented with Sarma and MIT postdoc Jonathan Jesneck that computationally combines many different images taken with an inexpensive low-resolution
infrared camera to produce a high-resolution mosaic image. That year Sarma, Phan, and Jesneck launched Essess to further develop its technology,
billions of dollars could be saved. Not just finding the culprits These early innovations to the hardware have nabled Essess to have this large-scale,
software-analytics approach, says Sarma, who is now Essessboard director. For utility companies, this means pinpointing home and building owners who are more or less likely to implement energy-efficient measures.
To do so, Sarma helped develop software that brings in household and demographic data such as information on householdsmortgage payments
age of tenants, number of children, and utility bills. This has since been developed further by Essess engineers.
Based on data from across the United states, for example, a household with three children is about 8 percent more likely to seal up leaks than a household with two children,
Essess President and CEO Tom Scaramellino says. t not just figuring out who the worst culprits are who wasting the most energy
because there are customers that can be wasting energy, but theyl never fix it, he says. here the actual energy waste and the psychological component to do something about it.
Those are two distinct analyses we layer on top of one another. Results for utilities companies indicate for instance, which zip codes have homes with the most leaky attics and, among those,
which owners are most likely to install attic insulation. Through this process, called the Thermal Analytics Program,
and air conditioning (HVAC) systems, which eat up about 50 percent of energy used in homes and buildings.
HVAC system efficiency is affected by the system itself, by household behavioral factors such as thermostat and window usage and
finally, by the building envelope. But companies measuring HVAC efficiency today, by reading meters and using other data,
have no building-envelope scans, so they can really determine if the envelope is indeed the culprit.
Essess, on the other hand, has all that information. f we see high meter usage that corresponds to really high HVAC load,
but see a really strong envelope, we know there probably something going on that abnormal and has to be addressed by an HVAC contractor,
Scaramellino says. Reality: A tough customer While Essess was Sarma third startup, it still came with some significant challenges.
And constant tweaks had to be made to the GPS SYSTEM that required more sophisticated software. hen youe driving around
There also the software. ou get the system running and realize there a tree in front of the building and,
in the image, it hard to figure out where the tree is and where the building is,
Sarma says. That when they had to install the Lidar system, to better differentiate building facades from the surrounding environment.
What was perhaps the most surprising and challenging aspect, Sarma says, was finding how closely coupled the hardware was to the software. his is truly mechatronic,
he says. small change to the hardware could have profound effects on the software. You may say,
el switch the frame rate of the cameras to catch more data, but that changes everything else in the software.
You really have to think about everything together. Now in its fourth iteration the technology constant refining for real-world applications has helped Essess develop a very sophisticated system,
Sarma says. eality is a tough customer to wrestle down, he says, ut that what engineering all about. s
#MIT researchers design tailored tissue adhesives After undergoing surgery to remove diseased sections of the colon, up to 30 percent of patients experience leakage from their sutures,
Many efforts are under way to create new tissue glues that can help seal surgical incisions
The researchers found that a sealant they had developed previously worked much differently in cancerous colon tissue than in colon tissue inflamed with colitis. The finding suggests that for this sealant
scientists must take into account the environment in which the material will be used, instead of using a ne-size fits allapproach,
a research scientist at MIT Institute for Medical science and Engineering (IMES) and senior author of a paper describing the findings in the Jan 28 online edition of Science Translational Medicine. e present a new paradigm by
Detailed study of tissue and biomaterial interactions can open a new chapter in precision medicine,
where biomaterials are chosen and rationally designed to match specific tissue types and disease states. After characterizing the adhesive material performance in different diseased tissues,
the researchers created a model that allows them to predict how it will work in different environments,
opening the door to a more personalized approach to treating individual patients. Elazer Edelman, the Thomas D. and Virginia W. Cabot Professor of Health Sciences and Technology and a member of IMES, is also a senior author of the paper.
The paper lead authors are graduate student Nuria Oliva and former graduate student Maria Carcole. Exploring material properties Artzi
and Edelman originally developed this tissue glue several years ago by combining two polymers dextran (a polysaccharide) and a highly branched chain called dendrimer.
In a 2009 paper, the researchers demonstrated that such adhesives work better when tailored to specific organs.
what happens when an adhesive is used in the same organ but under different disease conditions.
However, it performed worse in tissue inflamed with colitis than in healthy tissue. Further studies of the molecular interactions between the adhesive
The tissue glue works through a system where molecules in the adhesive serve as eysthat interact with ockschemical structures called amines found in abundance in structural tissue known as collagen.
but rather, disease type and state-dependent, says Artzi, who is also an assistant professor at Harvard Medical school.
Predicting adhesion Using this data, the researchers created a model to help them alter the composition of the material depending on the circumstances.
By changing the materialsmolecular weight the number of keys attached to each polymer, and the ratio of the two polymers, the researchers can tune it to perform best in different types and states of tissue.
An inherent property of the adhesive is that any unused keys are absorbed back into the polymer,
preventing them from causing any undesired side effects. This would allow the researchers to create two
or three different versions that could cover a wide range of tissues. e can take a biopsy from a patient for a quick readout of disease state that would serve as an input for our model,
and the output is the precise material composition that should be used to attain adequate adhesion,
Joseph Bonventre, chief of the renal unit and director of the bioengineering division at Brigham and Women Hospital in Boston, agrees that the study represents an important step toward a more personalized approach. ou want the best adhesive possible,
rather than developing biomaterials that try to work for all conditions. Doctors have begun using this kind of personalized approach
when choosing drugs that match individual patientsgenetic profiles, but it has not yet spread to the selection of biomaterials such as tissue glue.
The MIT team now hopes to move the sealant into clinical trials and has founded a company to help that process along. t something that we want to do as rapidly as possible,
Edelman says. ee excited. It not often that you have a technology that is this close to clinical introduction.
The new findings using a layer of one-atom-thick graphene deposited on top of a similar 2-D layer of a material called hexagonal boron nitride (hbn) are published in the journal Nano Letters.
The work is authored co by MIT associate professor of mechanical engineering Nicholas Fang and graduate student Anshuman Kumar
and their co-authors at IBM T. J. Watson Research center, Hong kong Polytechnic University, and the University of Minnesota.
Although the two materials are structurally similar both composed of hexagonal arrays of atoms that form two-dimensional sheets they each interact with light quite differently.
Many researchers see improved interconnection of optical and electronic components as a path to more efficient computation and imaging systems.
Light interaction with graphene produces particles called plasmons while light interacting with hbn produces phonons.
the plasmons and phonons can couple, producing a strong resonance. The properties of the graphene allow precise control over light,
Phaedon Avouris, a researcher at IBM and co-author of the paper, says, he combination of these two materials provides a unique system that allows the manipulation of optical processes. he combined materials create a tuned system that can be adjusted to allow light only of certain specific wavelengths
to create tiny optical waveguides, about 20 nanometers in size the same size range as the smallest features that can now be produced in microchips.
This could lead to chips that combine optical and electronic components in a single device, with far lower losses than when such devices are made separately and then interconnected,
they say. Co-author Tony Low, a researcher at IBM and the University of Minnesota, says,
ur work paves the way for using 2-D material heterostructures for engineering new optical properties on demand. nother potential application,
because the material naturally works at near-infrared wavelengths, this could enable new avenues for infrared spectroscopy,
Fang says, of biomolecules placed on the hybrid material surface. Sheng Shen, an assistant professor of mechanical engineering at Carnegie mellon University who was involved not in this research,
says, his work represents significant progress on understanding tunable interactions of light in graphene-hbn.
The work is retty criticalfor providing the understanding needed to develop optoelectronic or photonic devices based on graphene and hbn,
he says, and ould provide direct theoretical guidance on designing such types of devices. I am excited personally very about this novel theoretical work. he research team also included Kin Hung Fung of Hong kong Polytechnic University.
The work was supported by the National Science Foundation and the Air force Office of Scientific research
#Defusing bombs by color This March, Cambodia held its first national-level science festival at the Royal University of Phnom penh,
attracting over 10,000 young students to the science booths over the course of three days.
At one table, Allen Tan, the country director for Cambodia of the Golden West Humanitarian Foundation, held 3-D printed land mine models, decked in bright red, white,
and yellow colors to demonstrate the safe and dangerous parts. Nearby, J. Kim Vandiver, mechanical engineering professor and director of the MIT Edgerton Center, helped his wife, Kathy Vandiver, community outreach education and engagement director at the Center for Environmental Health Sciences
run a large booth of"Atoms and Molecules"kits. Tan and Vandiver had a lot to be excited about:
This science festival was unpredicted an benefit of an association that had begun with a brainstorming session in Phnom penh on ways to improve the training of people who work with unexploded mines and other remnants of conflict in Cambodia and around the world.
The demining process, called explosive ordnance disposal (EOD), is dangerous but necessary work. It is estimated that there are still 4 to 6 million unexploded pieces of ordnance in Cambodia,
which was bombed heavily during the Vietnam war. The repercussions have been severe: Between 1979 and 2013, there were over 40,000 reported injuries and nearly 20,000 fatalities due to unexploded land mines.
The U s. State department helps countries such as Cambodia train and deploy EOD teams, but, inherently, the training and deployment are difficult.
Trying to alleviate this problem, Tan and Vandiver came up with the idea to use 3-D-printed training models.
There are several advantages of 3d printed devices over 40-year-old real devices that have been rendered inert.
First, there is danger in disarming the real devices, as well as some difficulty in obtaining them in sufficient quantities to use in training.
Training with 3-D-printed versions is also more effective because students can assemble and disassemble such objects
and clearly understand how the various brightly colored components interact. An additional major advantage is the ability to bring these models on commercial airplanes,
whereas real parts of bombs are allowed never. Vandiver made the organization first 3-D printed land mine example from an existing computer-aided design (CAD) model of a Russian antipersonnel landmine.
The U s. State department was impressed so with the prototype and proposal from the Golden West Humanitarian Foundation that they soon provided funding to design
and create a training set consisting of 10 explosive devices commonly encountered by workers in Cambodia.
The closest 3-D printers however, were at the Singapore University of Technology and Design (SUTD.
Advanced ordinance teaching materials (AOTM) were developed in the Golden West Design Lab in collaboration with faculty from MIT and the Singapore University of Technology and Design.
Video: Golden West Humanitarian Foundationfortuitously, Vandiver was participating at the time in a collaboration between MIT and SUTD.
He realized the project would be a great opportunity for SUTD and MIT students to improve their CAD skills
and learn to perfect 3-D printing. Ten months ago, the Golden West Foundation completed its first complete set of 3-D-printed models, ready for use in training.
Vandiver contribution to the final training set was introducing modern pedagogical approaches to the training of EOD staff,
who were not fluent in English and had little education in engineering and science. True to his Edgerton Center roots
he helped Tan and others adopt the use of active learning in EOD training. Instead of the traditional, default lecture style,
students were expected to disassemble and work with the 3-D printed models to learn by discovery how different bombs
and mines worked. In these 3-D models, a simple mapping of colors showed the crucial pieces:
yellow is explosive material, red is the firing pin, and blue is inert structural material. t was important that they take them apart
and put them together, commented Vandiver, ecause then they would really remember it. andiver, who collaborated closely with Institute Professor Harold ocedgerton in the 1970s,
founded the Edgerton Center in 1992 as a legacy to Edgerton belief in the power of earning by doing.
He is a professor of mechanical and ocean engineering and also served as a lieutenant in the U s army Corps of Engineers in Vietnam in 1970-1971.
Vandiver was drawn to the Golden West Foundation EOD project because of his interest in engineering technology for developing countries.
While working at SUTD in Singapore in 2012 Vandiver visited one of his graduate students working on an EOD project in Cambodia.
It was on this visit that he met with Tan and engaged with him in a conversation about how to involve SUTD and MIT students in meaningful, real projects.
This brainstorming session produced the idea to engage student interns in the computer-aided design of training objects.
The completed set of 10 3-D models of mortar, artillery, and bomb fuses have been received well in the humanitarian EOD community.
Golden West is receiving orders from around the world for models made on 3-D printers set up by Golden West in Phnom penh.
SUTD and MIT student interns travel to Cambodia to help with design and production in coordination with John Wright, the project engineer at Golden West headquarters in Cambodia.
The training set costs approximately $7, 000 and may be shipped as ordinary luggage on commercial flights.
The United nations has ordered also sets for EOD training in Sub-saharan africa. Because of the high demand for these effective, portable training sets, the U s. Department of state has funded an extension of the project to produce training sets for cluster bombs and land mines.
There have also been unexpected side effects, such as Cambodia first national science festival. Modeled on the Cambridge Science Festival and the U s. Science and Engineering Festival in Washington
this fair introduced middle school-aged kids to many facets of engineering. Tan hopes the festival will help Cambodian students see that science
and engineering education can make it possible for them to make important contributions to their home and country.
Today, the Golden West Humanitarian Foundation continues to make EOD training sets, and is looking at more ways to improve EOD education using technology.
Vandiver, on top of other MIT and Edgerton Center-related work, stays in contact and continues to be involved in projects that make an impact in developing countries
#Vanishing friction Friction is all around us, working against the motion of tires on pavement, the scrawl of a pen across paper,
and even the flow of proteins through the bloodstream. Whenever two surfaces come in contact, there is friction,
except in very special cases where friction essentially vanishes a phenomenon, known as uperlubricity, in which surfaces simply slide over each other without resistance.
Now physicists at MIT have developed an experimental technique to simulate friction at the nanoscale. Using their technique,
the researchers are able to directly observe individual atoms at the interface of two surfaces
and manipulate their arrangement, tuning the amount of friction between the surfaces. By changing the spacing of atoms on one surface,
Vladan Vuletic, the Lester Wolfe Professor of Physics at MIT, says the ability to tune friction would be helpful in developing nanomachines tiny robots built from components the size of single molecules.
Vuletic says that at the nanoscale, friction may exact a greater force for instance, creating wear and tear on tiny motors much faster than occurs at larger scales. here a big effort to understand friction and control it,
because it one of the limiting factors for nanomachines, but there has been relatively little progress in actually controlling friction at any scale,
along with graduate students Alexei Bylinskii and Dorian Gangloff, publish their results today in the journal Science.
Learn about the technique MIT physicists developed to simulate friction at the nanoscale. Video: Melanie Gonick/MIT (with computer simulations from Alexei Bylinkskii) Friction and force fieldsthe team simulated friction at the nanoscale by first engineering two surfaces to be placed in contact:
an optical lattice, and an ion crystal. The optical lattice was generated using two laser beams traveling in opposite directions,
When atoms travel across such an electric field, they are drawn to places of minimum potential in this case, the troughs.
an ion crystal essentially, a grid of charged atoms in order to study friction effects, atom by atom.
To generate the ion crystal, the group used light to ionize, or charge, neutral ytterbium atoms emerging from a small heated oven,
and pull the ion crystal across the lattice, as well as to stretch and squeeze the ion crystal,
much like an accordion, altering the spacing between its atoms. An earthquake and a caterpillarin general, the researchers found that
when atoms in the ion crystal were spaced regularly, at intervals that matched the spacing of the optical lattice, the two surfaces experienced maximum friction,
much like two complementary Lego bricks. The team observed that when atoms are spaced so that each occupies a trough in the optical lattice,
when the ion crystal as a whole is dragged across the optical lattice, the atoms first tend to stick in the lattice troughs,
bound there by their preference for the lower electric potential, as well as by the Coulomb forces that keep the atoms apart.
If enough force is applied, the ion crystal suddenly slips, as the atoms collectively jump to the next trough. t like an earthquake,
Vuletic says. here force building up, and then there suddenly a catastrophic release of energy. he group continued to stretch
and squeeze the ion crystal to manipulate the arrangement of atoms, and discovered that if the atom spacing is mismatched from that of the optical lattice,
friction between the two surfaces vanishes. In this case the crystal tends not to stick then suddenly slip,
but to move fluidly across the optical lattice, much like a caterpillar inching across the ground.
For instance, in arrangements where some atoms are in troughs while others are at peaks, and still others are somewhere in between,
as the ion crystal is pulled across the optical lattice, one atom may slide down a peak a bit,
releasing a bit of stress, and making it easier for a second atom to climb out of a trough
not only for realizing nanomachines, but also for controlling proteins, molecules, and other biological components. n the biological domain, there are various molecules
and atoms in contact with one another, sliding along like biomolecular motors, as a result of friction or lack of friction, Gangloff says. o this intuition for how to arrange atoms so as to minimize
or maximize friction could be applied. obias Schaetz, a professor of physics at the University of Freiburg in Germany, sees the results as a lear breakthroughin gaining insight into therwise inaccessible fundamental physics.
The technique he says, may be applied to a number of areas, from the nanoscale to the macroscale. he applications and related impact of their novel method propels a huge variety of research fields investigating effects relevant from raft tectonics down to biological systems
and motor proteins, says Schaetz, who was involved not in the research. ust imagine a nanomachine where we could control friction to enhance contact for traction,
or mitigate drag on demand. his work was funded in part by the National Science Foundation and the National Science and Engineering Research Council of Canada a
#Toward tiny, solar-powered sensors The latest buzz in the information technology industry regards he Internet of thingsthe idea that vehicles, appliances, civil-engineering structures, manufacturing equipment,
and even livestock would have embedded their own sensors that report information directly to networked servers,
aiding with maintenance and the coordination of tasks. Realizing that vision, however, will require extremely low-power sensors that can run for months without battery changes or, even better,
that can extract energy from the environment to recharge. Last week, at the Symposia on VLSI Technology And circuits, MIT researchers presented a new power converter chip that can harvest more than 80 percent of the energy trickling into it
even at the extremely low power levels characteristic of tiny solar cells. Previous ultralow-power converters that used the same approach had efficiencies of only 40 or 50 percent.
Moreover, the researcherschip achieves those efficiency improvements while assuming additional responsibilities. Where most of its ultralow-power predecessors could use a solar cell to either charge a battery
or directly power a device, this new chip can do both, and it can power the device directly from the battery.
All of those operations also share a single inductor the chip main electrical component which saves on circuit board space
but increases the circuit complexity even further. Nonetheless the chip power consumption remains low. e still want to have battery-charging capability,
and we still want to provide a regulated output voltage, says Dina Reda El-Damak, an MIT graduate student in electrical engineering and computer science and first author on the new paper. e need to regulate the input to extract the maximum power,
and we really want to do all these tasks with inductor sharing and see which operational mode is the best.
And we want to do it without compromising the performance, at very limited input power levels 10 nanowatts to 1 microwatt for the Internet of things.
The prototype chip was manufactured through the Taiwan Semiconductor Manufacturing Company's University Shuttle Program. Ups and downs The circuit chief function is to regulate the voltages between the solar cell, the battery,
and the device the cell is powering. If the battery operates for too long at a voltage that either too high or too low, for instance, its chemical reactants break down,
and it loses the ability to hold a charge. To control the current flow across their chip, El-Damak and her advisor, Anantha Chandrakasan,
the Joseph F. and Nancy P. Keithley Professor in Electrical engineering, use an inductor, which is a wire wound into a coil.
When a current passes through an inductor, it generates a magnetic field which in turn resists any change in the current.
Throwing switches in the inductor path causes it to alternately charge and discharge, so that the current flowing through it continuously ramps up
and then drops back down to zero. Keeping a lid on the current improves the circuit efficiency,
since the rate at which it dissipates energy as heat is proportional to the square of the current.
Once the current drops to zero, however, the switches in the inductor path need to be thrown immediately;
otherwise, current could begin to flow through the circuit in the wrong direction, which would drastically diminish its efficiency.
The complication is that the rate at which the current rises and falls depends on the voltage generated by the solar cell,
which is highly variable. So the timing of the switch throws has to vary, too.
El-Damak and Chandrakasan use an electrical component called a capacitor, which can store electrical charge.
The higher the current, the more rapidly the capacitor fills. When it full, the circuit stops charging the inductor.
The rate at which the current drops off however, depends on the output voltage, whose regulation is the very purpose of the chip.
Since that voltage is fixed, the variation in timing has to come from variation in capacitance.
El-Damak and Chandrakasan thus equip their chip with a bank of capacitors of different sizes.
As the current drops, it charges a subset of those capacitors, whose selection is determined by the solar cell voltage.
Once again, when the capacitor fills, the switches in the inductor path are flipped. n this technology space,
there usually a trend to lower efficiency as the power gets lower, because there a fixed amount of energy that consumed by doing the work,
says Brett Miwa, who leads a power conversion development project as a fellow at the chip manufacturer Maxim Integrated. f youe only coming in with a small amount,
it hard to get most of it out, because you lose more as a percentage.
El-Damak design is unusually efficient for how low a power level she at. ne of the things that most notable about it is that it really a fairly complete system,
he adds. t really kind of a full system-on-a chip for power management. And that makes it a little more complicated
Overtext Web Module V3.0 Alpha
Copyright Semantic-Knowledge, 1994-2011