Spot News Roundup

Apr 18 2018 | By Jesse Adams

$10 MILLION FOR BREAKTHROUGH DISCOVERIES
Columbia Engineering has announced a $10 million grant from the Blavatnik Family Foundation funding innovative research at the intersection of engineering and health and expediting the development, application, and commercialization of breakthrough discoveries. The foundation is headed by American industrialist and philanthropist Len Blavatnik MS’81, founder of Access Industries and a graduate of Columbia Engineering, where he studied computer science.

Len Blavatnik, head of the Blavatnik Family Foundation. Photo by Timothy Lee Photographers.
 

“We are deeply grateful for this transformative gift that will fund pioneering research for the next 10 years,” said Dean Mary C. Boyce.

“With his generous gift, Len Blavatnik is furthering our vision of Engineering for a Healthy Humanity by supporting a research pipeline in health and medical research, from doctoral students just beginning their inquiries, to faculty at the crossroads of engineering and medicine, to funding the translation of their research from the laboratory to industry.”

The grant is supporting two major initiatives. The first, the Blavatnik Doctoral Fellows, is an elite cohort of  early career graduate researchers working at the junction of engineering and health who will receive recognition and financial support. The second, the Blavatnik Fund for Engineering Innovations in Health, will provide annual seed funding for interdisciplinary and translational research projects promoting the transition of ideas and research to the market through licensing or startup ventures.

“My goal is to support research that is interdisciplinary and nontraditional, because that is where the truly revolutionary breakthroughs will come from,” said Blavatnik. “I am drawn to and intrigued by the work of smart, young scientists and engineers as a way to leverage their enormous brainpower to improve health and life.”

 

KAREN KASZA AND JAMES TEHERANI WIN NSF CAREER AWARDS
Karen Kasza and James Teherani have won Faculty Early Career Development (CAREER) awards, one of the most competitive honors given by the  National Science Foundation (NSF).

Karen Kasza, Clare Boothe Luce Assistant Professor in the Department of Mechanical Engineering, won the CAREER award for her proposal “Biophysical Mechanisms Underlying the Generation of Tissue Structure and Mechanics during Drosophila Development.” Kasza uses approaches from engineering, biology, and physics to understand and control how cells self-organize into functional tissues with precise mechanical and structural properties.

For her CAREER project, Kasza is combining biomechanical and confocal imaging studies with optogenetic tools for light-gated manipulation of cellular force generation and mechanics to study embryonic development. Her work could lead to a deeper understanding of tissue mechanics and movements as well as shed light on human development, including what happens when tissue movements are improperly regulated and result in birth defects. She plans to develop tools and approaches to enable the building of multicellular tissues and new, biologically inspired materials.

James Teherani, assistant professor in the Department of Electrical Engineering, won for his proposal “Exploiting Many-Particle Physics for Low-Energy Nanoelectronics.” Teherani studies emerging semiconductor materials and devices. His group conducts both theoretical and experimental research—from quantummechanical simulations to nanoscale fabrication—to explain the physics of novel devices made from a new class of two-dimensional materials that form atomically thin sheets.

His NSF project is focused on experimentally demonstrating the Auger FET, a new type of field-effect transistor based on the many-particle physics of Auger generation that potentially could enable ultralow-energy electronics. In setting the foundational physics for this innovative device concept, Teherani also hopes to broaden the understanding of Auger generation and recombination processes in quantum structures, which is critical for improving efficiency in LEDs, lasers, and photodetectors. Ultralow-energy Auger FETs would empower a range of new applications, and their use in existing applications would considerably decrease energy consumption.

 

HONORS GALORE
Columbia Engineering faculty continue to accrue some of the most prestigious honors in their fields.

Shih-Fu Chang, senior executive vice dean, the Richard Dicker Professor of Telecommunications, and professor of electrical engineering and of computer science, was named a 2017 Fellow of the Association for Computing Machinery, cited for his “contributions to large-scale multimedia content recognition and multimedia information retrieval.” Director of the Digital Video Multimedia (DVMM) Lab and a member of the Data Science Institute, Chang has pioneered the development of new techniques and systems for multimedia content analysis, retrieval, and communications while addressing fundamental challenges in computer vision and machine learning.

Qiang Du, the Fu Foundation Professor of Applied Mathematics, was elected a 2017 Fellow of the American Association  for the Advancement of Science for his “distinguished contributions to the field of applied and computational  mathematics, particularly for theoretical analysis and numerical simulations of mathematical models in various applications.” Head of the Computational Mathematics and Multiscale Modeling (CM3) group, Du specializes in many areas of applied mathematics and computational sciences, including modeling, analysis, algorithms, and computation, with applications in physical, biological, materials, and information sciences.

Donald Goldfarb, the Alexander and Hermine Avanessians Professor of Industrial Engineering and Operations Research (IEOR), won the John von Neumann Theory Prize from the Institute for Operations Research and the Management Sciences in recognition of “fundamental contributions, theoretical and practical, that have, and continue to have, a significant impact on the field of optimization.” Goldfarb’s teaching and research interests include algorithms for linear, quadratic, semidefinite, convex, and general nonlinear programming; network flows; large sparse systems; and applications in robust optimization, finance, machine learning, and imaging. On the faculty since 1982, Goldfarb headed the IEOR department for many years and served as acting dean (1994–95) and interim dean (2012–13).

Additionally, Bjarne Stroustrup, a visiting professor of computer science and a managing director in the technology division of Morgan Stanley, was awarded the National Academy of Engineering’s prestigious Charles Stark Draper  Prize for Engineering for creating the C++ programming language.

Shih-Fu Chang, recognized as an ACM fellow for his transformative role in advancing technology in the digital age. Photo by Jeffrey Schifman.

 

SINGLE-MOLECULE TRANSISTORS
In the field of molecular electronics, researchers have long sought to build a device that achieves a quantized, controllable flow of charge at room temperature. But to accomplish that, researchers had to first demonstrate that single molecules can function as reproducible circuit elements, such as transistors or diodes, that can readily operate at human-friendly climes.

A team led by Latha Venkataraman, professor of applied physics and chemistry at Columbia Engineering, and Xavier Roy, assistant professor of chemistry, has reproducibly demonstrated current blockade—the ability to switch a device from the insulating to the conducting state—using atomically precise molecular clusters at room temperature.  The team’s result, a first, could lead to shrinking electrical parts and boosting data storage and computing power.

Researchers created a single cluster of geometrically ordered atoms with an inorganic core made of just 14 atoms—resulting in a diameter of about 0.5 nanometers—and positioned linkers that wired the core to two gold electrodes, much as a resistor is soldered to two metal electrodes to form a macroscopic electrical circuit. Using a scanning tunneling microscope technique that they pioneered, they were able to characterize electrical responses as they varied the applied bias voltage. The technique allows them to fabricate and measure thousands of junctions with reproducible transport characteristics.

Some studies have used quantum dots to produce similar effects, but those results have not been reproducible. The Columbia team worked with smaller inorganic molecular clusters that were identical, so they knew exactly—down to the atomic scale—what they were measuring. They also tailored the clusters to explore how compositional alteration changes the clusters’ electrical response.

“Our collaborative effort here through the Columbia Nano Initiative bridges chemistry and physics, enabling us to experiment with new compounds, such as these molecular clusters, that may not only be more synthetically challenging, but also more interesting as electrical components,” Venkataraman said.

 

MORE LIFELIKE ROBOTS
Soft material robotics hold tremendous promise for areas where robots interact with humans. Unlike rigid robots, soft robots can replicate natural motion—grasping and manipulation—to provide medical and other types of assistance, perform delicate tasks, or pick up soft objects.

Previously, no material has been capable of functioning as soft muscle, due to an inability to exhibit the desired properties of high actuation stress and strain. Existing soft actuator technologies are typically based on inflating elastomer skins that expand when air or liquid is supplied, hindering miniaturization and the ability to work independently.

Solving a long-standing issue in creating untethered soft robots whose actions and movements can mimic natural biological systems, a group in mechanical engineering professor Hod Lipson’s Creative Machines Lab has developed a 3D-printable synthetic soft muscle, a unique artificial active tissue that does not require an external compressor or high-voltage equipment as did previous mechanical muscles.

To achieve an actuator capable of high strain and high stress coupled with low density, postdoctoral researcher Aslan Miriyev used a silicone rubber matrix combining the elastic properties and extreme volume change attributes of other material systems while also being easy to fabricate, of low cost, and made of environmentally safe materials. The new material has a strain density 15 times greater than natural muscle and can lift 1,000 times its own weight.

After being 3D-printed into the desired shape, the artificial muscle was electrically actuated with a wire and tested in a variety of robotic applications, showing significant expansion-contraction ability. Via computer controls, the autonomous unit can perform motion tasks in almost any design.

“We’ve overcome one of the final barriers to making lifelike robots,” said Lipson. “This is a big piece of the puzzle and, like biology, the new actuator can be shaped and reshaped a thousand ways.”

Researchers wired a single molecular cluster to gold electrodes to show that it exhibits a quantized and controllable flow of charge at room temperature. Image courtesy of Bonnie Choi.

An electrically actuated muscle with thin resistive wire in an expanded position using low-power characteristics (8V). Photo by Aslan Miriyev.

 

DEVELOPING WIRELESS REAL ESTATE
These days, bandwidth has become an increasingly rare commodity. The frequencies at which most electronic devices operate are filling fast and, like square footage in Manhattan, there’s a pressing need for more space.

One main culprit: almost all devices are reciprocal, meaning signals travel in the same manner in forward and reverse directions. Nonreciprocal devices, such as circulators, allow forward and reverse signals to traverse different paths and remain separated, but usually require special magnetic materials too bulky and expensive for use in consumer wireless electronics.

But now, a group led by Harish Krishnaswamy, associate professor of electrical engineering, has developed a new magnet-free way to enable nonreciprocal transmission of waves by using carefully synchronized highspeed transistor switches that route forward and reverse waves differently, all on a silicon chip operating at millimeter-wave frequencies. With such full-duplex communications, a transmitter and receiver operate simultaneously on the same frequency channel, potentially doubling data capacity within existing bandwidth.

“This gives us a lot more real estate,” said Krishnaswamy, whose Columbia high-Speed and Mm-wave IC (CoSMIC) Lab has been working with colleagues at UT-Austin on silicon radio chips for full-duplex communications for several years. Their method enables loss-free, compact, and extremely broadband nonreciprocal behavior applicable to a wide range of components.

The implications are vast and could be used to help operate self-driving cars and enable better VR headsets, which currently rely on a wired connection or tether to a computing device. Funded by sources including the National Science Foundation EFRI program, the DARPA SPAR program, and Texas Instruments, the researchers are working to improve their circulator’s linearity and isolation performance. Their long-term goal is to build a large-scale millimeter-wave fullduplex phased array system.

“This could revolutionize emerging 5G cellular networks, wireless links for virtual reality, and automotive radar,” Krishnaswamy said.

Chip microphotograph of the 25GHz fully integrated nonreciprocal passive magnetic-free 45nm SOI CMOS circulator based on spatiotemporal conductivity modulation. Image courtesy of Tolga Dinc.

 

ENGINEERING GRAPHENE
By recreating the electronic structure of graphene in a nanofabricated semiconductor device—in effect engineering “artificial graphene”—researchers at Columbia Engineering made an important breakthrough in physics and materials science with far-reaching implications for advanced optoelectronics and data processing.

The unique atomic arrangement of the carbon atoms in graphene makes an excellent platform for testing quantum phenomena difficult to observe in conventional materials systems. With its unusual electronic properties—the atoms can travel great distances before scattering—graphene is an outstanding conductor, and also displays other unique characteristics of electrons behaving as if they are relativistic particles moving close to the speed of light, attaining exotic properties not exhibited by nonrelativistic electrons.

But experiments on natural graphene face fundamental constraints: the positions of the atoms in its lattice are fixed in one arrangement. Creating artificial graphene has been a dream for condensed matter researchers, as it would possess more versatile properties and a lattice adaptable over a wide range of configurations.

“This milestone defines a new state of the art in condensed matter science and nanofabrication,” said Aron Pinczuk, professor of applied physics and physics at Columbia Engineering. “Semiconductor artificial graphene devices could be platforms to explore new types of electronic switches, transistors with superior properties, and even, perhaps, new ways of storing information based on exotic quantum mechanical states.”

Working with colleagues from Princeton, Purdue, and Istituto Italiano di Tecnologia, the researchers designed a layered structure of a standard semiconductor material that allowed electrons to move only within a very narrow layer, effectively a 2D sheet. They used nanolithography and etching to pattern a hexagonal lattice of sites in which electrons were laterally confined to make “artificial atoms” that interact quantum mechanically, similarly to how atoms share their electrons in solids.

Renderings of artificial graphene in a semiconductor. Etched pillars define the positions of quantum dots arranged in a hexagonal lattice. When spacing between quantum dots is sufficiently small, electrons can move between them. Images courtesy of Diego Scarabelli.

 

FLOATING SOLAR FUELS RIGS
In one hour, more solar energy hits Earth than humankind consumes in an entire year. What if that energy could be harnessed in a way that is economical, scalable, and sustainable?

Daniel Esposito, assistant professor of chemical engineering, has been studying water electrolysis—the splitting of water into oxygen and hydrogen fuel—as a way to convert electricity from solar photovoltaics (PV) into clean hydrogen fuel. Most of today’s hydrogen is produced from natural gas through a process that generates carbon dioxide, but water electrolysis using solar electricity from solar PV is a promising route to providing hydrogen without carbon emissions.

Esposito’s team has developed a photovoltaic-powered electrolysis device that can operate as a stand-alone platform  floating on open water, capable of producing hydrogen fuel from sunlight and water. The key innovation uses novel electrode configuration and electrolyzer architecture to exploit the buoyancy of water bubbles, which facilitates separation and collection of the hydrogen and oxygen gases efficiently—instead of using expensive and fragile membranes.

“Our design [is] particularly attractive for its application to seawater electrolysis, thanks to its potential for low cost and higher durability,” said Esposito, whose Solar Fuels Engineering Laboratory develops technologies that  convert solar energy into storable chemical fuels. “We believe that our prototype is the first demonstration of a practical membraneless floating photovoltaic-electrolyzer system and could inspire large-scale ‘solar fuels rigs’ that could generate large quantities of hydrogen fuel from abundant sunlight and seawater —without taking up any space on land or competing with fresh water for agricultural uses.”

The team is now refining their process for use in real seawater, which is more challenging than in laboratory conditions, and plans to develop modular designs for building larger systems.

“Our challenge is to find scalable and economical technologies that convert sunlight into a useful form of energy that can also be stored for times when the sun is not shining,” Esposito said. 

 

CONFRONTING THE OPIOID EPIDEMIC
The opioid epidemic is vast and multifaceted, costing the U.S. more lives just in the last year than were lost during the entire Vietnam War. Highly addictive and often obtained legally for pain, opioids are all the more dangerous because they are more accessible and can be stronger than any narcotics previously available.

In the tradition of design competitions that sparked interdisciplinary innovations for fighting Ebola and addressing urban water issues, the Columbia Opioid Design Challenge was kicked off in October by Dean Mary C. Boyce and Elizabeth Hillman, professor of biomedical engineering. Taking a multidisciplinary approach, the challenge drew more than 100 students from nearly every school in the University.

Over two intensive weeks—including sessions for refining ideas, perfecting pitches, and consulting with recovering addicts—teams came together to tackle the issue from various angles, including destroying excess pills, rapidly treating overdoses, and offering continuous support for people in recovery. In November, 15 teams made two-minute pitches before a panel of expert judges.

Ideas ranged from sensor-equipped wearables and affordable kits for testing the purity of street drugs to use of machine learning to assess the likelihood of patients becoming addicted. In the end, five teams won up to $2,500 each in the form of “opioid challenge grants” in addition to ongoing mentorship to further develop their work. Five more teams were awarded runner-up prizes including $300 of materials for use in the Columbia Engineering Makerspace.

Groups continue to develop their prototypes and collaborate with faculty, experts, and peers. They will have a shot at an even bigger prize pool this spring at the Columbia Venture Competition and through outside opportunities from groups like Cisco and VentureWell.

Rendering of a hypothetical largescale “solar fuels rig” operating on the open sea. The rig uses sunlight to split seawater into H2 and oxygen. Photo by Justin Bui.

 

TRACKING FOOD-BORNE ILLNESSES
The New York City Health Department uses a system created with Columbia engineers to track food-borne illnesses via Yelp. So far, the project, which is based on keywords that appear in restaurant reviews, has identified at least 10  outbreaks of food-borne illness and helped city staff identify approximately 1,500 complaints of food-borne illness annually since 2012.

Every year, thousands of people in New York City become sick from consuming food or drink contaminated with harmful bacteria, viruses, or parasites. The Health Department and Columbia Engineering computer scientists continue to expand their system to include other social media sources, such as Twitter, added in late 2016.

“Effective information extraction regarding food-borne illness from social media is of high importance—online restaurant review sites are popular, and many people are more likely to discuss food poisoning incidents on such sites than on official government channels,” said Luis Gravano and Daniel Hsu, professors of computer science and members of the Data Science Institute.

“Using machine learning has already had a significant impact on the detection of outbreaks of food-borne illnesses.”

The Health Department reviews and investigates all complaints of suspected food-borne illness in the five boroughs. Since 2012, the department has identified and investigated over 28,000 suspected complaints of food-borne illness overall, including through its complaint system.

“The collaboration with Columbia University to identify reports of food poisoning in social media is crucial to improve food-borne illness outbreak detection efforts in New York City,” said Health Department epidemiologists Vasudha Reddy and Katelynn Devinney.

“The incorporation of new data sources allows us to detect outbreaks that may not have been reported and for the earlier identification of outbreaks to prevent more New Yorkers from becoming sick.”

 

Researchers led by Lance Kam and Helen Lu used soft fibers (red) to activate T cells (green), improving cellular immunotherapy. Image courtesy of Lance Kam.

LIVING DRUGS
T cells, a key component of the body’s immune response to pathogens, are fighting cancer as part of a new class of therapeutic approaches promising more precise and longer-lasting mitigation than traditional chemical-based approaches. Such “living drugs” are poised to transform medicine, with a growing number of cellular therapies receiving FDA approval.

A major bottleneck in such therapies is producing enough high-quality T cells, typically isolated from patients and  then modified and grown outside the body in bioreactors. T cells from patients undergoing treatment for cancer often show reduced function and are especially difficult to grow.

A Columbia Engineering team led by biomedical engineering faculty Lance C. Kam and Helen H. Lu has developed a new method for improving their manufacture. Utilizing a polymer mesh to activate T cells, their approach simplifies processing compared to current systems and builds the mesh fibers out of a mechanically soft material that helps improve T cell growth.

“This soft mesh material increases the number of functional cells that can be produced in a single step,” Kam says. “What’s especially exciting is that we’ve been able to expand cells isolated from patients undergoing treatment for leukemia. These cells are often very difficult to activate and expand, and this has been a barrier to using cellular immunotherapy for the people who need it.”

Researchers have long known that other cell types can sense a material’s mechanical stiffness, as when the rigidity of a material used to culture stem cells directs differentiation, but a similar effect was not expected in T cells.

Early experiments from Kam’s Microscale Biocomplexity Laboratory group revealed that T cells can sense the rigidity of materials commonly used in the laboratory. His group partnered with Lu’s Biomaterials and Interface Tissue Engineering Laboratory to create a microfiber-based platform for clinical use.

Beyond simplifying and improving processes of cell expansion, Kam and Lu expect that the mesh platform will eventually have applications beyond immunotherapy.

“It is truly exciting to see how these bioinspired matrices can direct cell function and be successfully used for T cell therapy,” Lu said.