Interdisciplinary Research Collaborations
Both undergraduate and graduate students work collaboratively on interdisciplinary projects. The opportunity for undergraduates to perform research by directly working with faculty and graduate students is a feature the faculty in the Division of Engineering cherishes. Upon graduation, it is the early training in the laboratory that provides students with a leg-up on the competition when applying for jobs, graduate schools, etc. If you think outside the box and enjoy tackling broad and challenging problems, interlaced with other disciplines, the Division of Engineering can provide you with those opportunities.
Highlights include:
Implantable Microelectronics for the Brain
Enabling neurologically severely disabled individuals, such as those with paralysis from spinal cord injury, to directly employ their command thoughts from the brain to operate man-made devices and assistive machines offers a potential intersection with brain science with modern engineering technologies of significant societal and health care value. Spinal cord injuries and degenerative diseases involve very large populations of people worldwide, whose quality of life is much impaired, even if the brain is cognitively functional. Recent pioneering work at Brown in Professor John Donoghue’s laboratories in Neuroscience has shown how, using a simple brain implanted electrical probe, with cabling to external signal processing electronics, has enabled a tetraplegic patient to control a cursor on a computer screen for communication activities such as reading email, typing messages, drawing elementary freeform shapes, and operating a open-close prosthetic hand.
To create a new paradigm in interfacing the brain to external world, a Brown engineering team has joined neuroscientists, neurosurgeons, and computer scientists on campus, with neurologists at Harvard Medical School and a neurotechnology company (Cyberkinetics Inc), to develop a compact implantable neural recording chip for wireless extraction of signals from the brain. The Brown engineering team is led by Professor Arto Nurmikko and includes Asst. Prof. (Research) Yoon-Kyu Song, senior engineers/lecturers William Patterson and Chris Bull, together with a group of graduate and undergraduate students. The team has already developed a novel neural signal sensor where ultralow power, specialized signal processing microelectronic chips are integrated with multielectrode cortical probe arrays. With the inclusion of an on-board infrared optical source for brain signal transmission, the ultimate aim of the team is to implement a high speed digital neural signal communication system from the brain. In initial engineering tests the new microsystem shows ability for high-fidelity recording of neural “spikes” animals. The research is motivated by the eventual goal of offering severely paralyzed people entirely new means for operating external devices by direct command signals from the brain.
Toxicity of Nano-Materials
According to the Institute of Medicine, the federal government last year invested nearly $1 billion in nanotechnology, yet little is known about how engineered nano-particles affect human health. Professor Robert Hurt (Engineering, FTCP) is leading a diverse research team composed faculty members with various backgrounds, Professors Kane (Pathology and Laboratory Medicine), Morgan (Pharmacology, Physiology and Biotechnology), Brown (Sociology), and Crawford (Engineering, ESCE), to study the health and societal effects of toxicity of nano-particles. Major international investments in nanotechnology R&D have produced a plethora of new nanoscale materials whose biological effects following inhalation or dermal exposure are largely unknown, and this uncertainty has become a major obstacle for successful commercial development. The Brown team is synthesizing and characterizing a panel of carbon nanomaterials and subjecting them to new molecular and cellular assays being developed for nanotoxicology studies. The goal is to establish mechanistic links between the toxicity and specific nanomaterial features such as size, shape, and surface chemistry. One long term goal of this approach is to identify ways of processing or re-formulating nanomaterials materials to reduce or eliminate their risk to human health and the environment. The NIRT grant also features a collaboration between the science P.Is, Daniel Sarachick and Stephen Morin in Brown's Office of Environmental Health and Safety Office focused on developing and disseminating a rational policy for nanomaterial safety in university research laboratoriesWith a new four-year National Science Foundation grant, the group will create and test a variety of materials to see how they interact with human and animal cells. The aim: Find out which sizes, shapes, compounds, and coatings damage or kill cells. Such information can be used to manufacture nontoxic types.
High Performance Nano-Composites
Researchers from all four research groups in the Division of Engineering have joined in an interdisciplinary team with General Motors to develop tough ceramic nanocomposite coatings. Professors Brian Sheldon (Materials), William Curtin (Solid Mechanics), Gregory Crawford (ESCE), and Robert Hurt (FTCP) have a four-year NSF-funded Nanoscale Interdisciplinary Research Team (NIRT) grant focused on the synthesis and characterization of these novel ceramic/carbon nanocomposites. Supramolecular approaches developed at Brown are being used to control the crystal structure and mechanical properties of carbon nanofibers. Several different fabrication methods are then employed to combine these reinforcements with a variety of ceramic matrix materials, to obtain coatings with superior mechanical properties. Nano-indentation is used to obtain information on the fracture behavior and the influence of nanoscale reinforcement, while the underlying fracture mechanisms are studied by a parallel computational modeling effort. The team is focusing on alumina, carbon, silicon carbide, alumina/carbon, and silicon nitride/carbon based coatings that have applications where hardness, abrasion resistance, superhydrophobicity, or antifouling properties are desired.
3D Free Form Models
An Interdisciplinary Program:
3D Free Form Models for Representation, Manipulation, and Recovery, of Shape with Applications to Archaeology and Virtual Sculpting.
This is a project, primarily funded by NSF, involving faculty, graduate students, and a number of undergraduate students from Computer Engineering, Archaeology, Applied mathematics, and Art devoted to modeling 2D and 3D shape, and inferring shape and geometric properties from images, video, dense-data laser scans, or a combination of these. Applications range from core computer-vision/pattern-recognition problems such as object recognition, 3D object and scene reconstruction, rapid prototyping, surveillance, to archaeological site-data interpretation such as automatic or interactive reconstruction of murals or ceramic vessels or solid objects from piles of unorganized fragments, mathematical modeling of large structures and 3D virtual viewing of these, and construction and searching over the internet of archaeological databases containing artifacts but also images, video clips and 3D dense-data laser scans and 3D reconstructions, and permitting measuring geometric properties of these data sets. The resulting research is providing new, and in some cases, revolutionary tools and concepts for both archaeological site analysis and computer-vision/pattern-recognition, and is fascinating for the participating individuals from the various disciplines.
Nano-Electronics
As CMOS technology downscales, computer architecture has to contend with defective devices operated in a noisy signal environment at low supply voltage. One possible scenario is the advent of fault-tolerant probabilistic computing. In this interdisciplinary project, we examine probabilistic-based design methodologies for nanoscale computer architectures based on Markov random fields (MRF). The MRF approach can express arbitrary logic circuits and the logic operation is achieved by maximizing the probability of correct state configurations in the logic network depending on the interaction of neighboring circuit nodes. The computation proceeds via probabilistic propagation of states through the circuit. Specifically, our goal is to develop techniques using Markov Random Fields that allows the architecture to dynamically adapt to faults in order to achieve robust computing requirements, thereby avoiding the need for actual fault detection and correction without harming performance. We have developed and simulated CMOS-based probabilistic circuit elements based on Markov random field (MRF) theory that use additional transistors and feedback loops to achieve significant noise immunity and ensure correct logic operations at supply voltage and signal-to-noise ratio so low as to render standard CMOS designs completely inoperable.
This is an interdisciplinary project that brings together researchers with expertise in device physics, image processing, computer architecture, circuit design, and fabrication. The team includes Professors R. Iris Bahar, Joseph Mundy, and Alexander Zaslavsky and Senior Research Engineering William Patterson. The students involved have been exposed to research areas beyond their immediate expertise, broadening their appreciation of the advanced devices and systems.
Probabilistic computing provides a new approach towards building more powerful fault-tolerant nanoarchitectures and systems. Our approach could lead to a paradigm shift in computing architecture.
Silicon Nanophotonic Devices
The creation of optically active devices in the silicon medium has been a goal for several generations of solid state scientists. The proud legacy continues and Brown University where Professor Jimmy Xu, graduate students and postdoctoral fellows in the Department of Physics and Division of Engineering (Electrical Sciences and Materials Sciences) are leading a collaboration with members of the Brown engineering and physics departments as well as members of the Electrical Engineering Department at the State University of New York, Stony Brook, materials scientists and physicists at Harvard University and photonic device physicists at Cornell University. The demonstration of laser action in nanopatterned silicon at Brown in 2005 was an important breakthrough, marking the first realization of lasing based on the optical activity of point defects in silicon. The research also indicates the potential to enhance the optical properties of silicon via nanoscale manipulation. Continued research associated with these collaborations is focused on the controlled introduction of optically active defects in silicon, new methods of nanoscale modification which allow for active tuning of the optical and electronic properties of silicon structures, and on novel new configurations wherein silicon is coupled to other emissive media, such as metals with a large plasmonic response or polymers with an excitonic response. The ongoing research is exciting both from the point of view of the nanoscale physicist and from the point of view of the optoelectronic engineer.
Direct nanoscale conversion of biomolecular signals into electronic information
The laboratory of emerging technology, led by Professor Jimmy Xu, at Brown has been a leading participant in a Multi-University Research Initiative (MURI) of the DoD for “Direct nanoscale conversion of biomolecular signals into electronic information”. This is a first major national initiative to interface biomolecules and nanoelectronics by developing a technology suite to engineer redox proteins and DNA and peptides to enable transduction of biomolecular activities into electronic information via self-assembling, self-addressing, and scalable nanoelectronic probe arrays. This work draws from expertise in the fields of biochemistry, electrochemistry, nanomaterials science, electrical engineering, microfluidics and nanoelectronics from multiple institutions – Brown, Boston College, University of Pittsburgh. Drexel University, University of Toronto, University of Florida, Naval Research Laboratory, and University of Virginia. To do this, we have devised several approaches to effectively interface biomolecules with nano- and micro-electronic circuitry in a way that preserves and enhances their inherent biological function. These systems developed to date are self-assembling and self-organizing by virtue of programmable molecular linking systems involving peptides, coiled coils and nucleic acids. This feature lends the systems scalability and renewability. Although the project is driven in the interest of basic science research, it has several immediate applications in arenas such as biosensors and bio-fuel cells.
Nanotechnology platforms for DNA sorting and identification
The Laboratory of Emerging Technologies has been in the pursuit of developing novel “Nanotechnology platforms for DNA sequencing”. A potential application is in DNA Identification, and it has been the focus of an collaboration with Robin Smith and Karen Lynch at the crime lab of the Rhode Island State and Lt. Dennis Pincince at the RI State Police Criminal Identification Unit, Professor Beth Zielinski-Habershaw at the University of Rhode Island, and Professor Anubhav Tripathi of fluidic mechanics at Brown. Three platforms are being developed to further basic science research of DNA-nanotube/nanopore interactions and to help speed up the DNA identification process in criminal investigation. The goal on this front is to develop fast, portable, disposable NanoChips (containing sieving nanotube or nanopore arrays) for forensic STR profiling.
Our lab also collaborates with Bharat Ramratnam’s team at the Lifespan/ Tufts/ Brown Center for AIDS Research Research (CFAR) at the Miriam Hospital in Providence, RI. This collaboration is focused on infectious disease prevention using carbon nanotubes and other nanomaterials (to be realized in the form of a cream, a pill, or an injection). The hope is to stop the infections at the mucosal lining, where the virus enters the body and the infection begins. So far, we have successfully delivered DNA and fluorophores into rectal tissue in vivo, and are working on delivering siRNA, getting effective oral delivery, and modifying our cargo.
DNA functionalized nanotube array technology
The Emerging Technology lab leads a multidisciplinary research effort and collaborates with researchers from Brown, Boston College, and Drexel University in developing novel materials designed using DNA nanotechnology. Funded under an Air Force MURI program, the five year grant has delivered technology solutions capable of detecting biological analytes on a nanoelectronic sensor platform. Housing the design, fabrication, and material analysis and processing facilities, this lab is able to tailor highly ordered carbon nanotube arrays geometrical and chemical properties.
Highly ordered arrays of carbon nanotubes whose chemical properties can be used to conjugate nanoparticle labeled DNA. By controlling the location of DNA conjugation sites, gold nanoparticles can be self-assembled to the designated particular spot on a nanotube in an array, and subsequently zinc oxide nanowires can be grown at the site of the gold nanoparticle.
Integrated zinc-oxide carbon nanotube wires were grown atop of the tip of carbon nanotubes selected in accordance with the instruction encoded in the DNA self-assembling process. The resultant Zinc Oxide nanowire – carbon nanotube heterojunction demonstrates its potential in nano-scale ultra-violet sensing.
Carbon nanotube nanoneedles
The Laboratory of Emerging Technologies has been developing a new device based on carbon nanotubes assembled into a nanoneedle. These nanoneedles can be as small as a few nanometers and as long as tens of microns, are mechanically strong, electrically highly conductive, and can be chemically functionalized. These devices could enable intracellular and biomolecular explorations that push the size, volume, and sensitivity limits.
In collaboration with Professor Stephen Helfand of cell biology, we utilized these nanoneedles in glucose detection of sample volumes less than one micro litter. In collaboration with researchers in biochemistry at Boston College and Brown, we are exploiting the use of the nanoneedles for DNA detection. In collaboration with Professor Anubhav Tripathi’s group in fluidic engineering and Professor Mierke Dale of molecular biology, we have begun the development of a new platform to enable single protein activity detection.
Biomedical spectroscopy of blood components with applications in emergency medicine, pediatrics, and laparoscopic surgery:
Diffuse reflectance spectroscopy of blood vessels can allow for the rapid determination of blood analyte concentrations in a nondestructive and noninvasive manner. This project has been funded primarily by NASA, Goldman Philanthropic Charles Culpeper Biomedical program, and seed funds from the office of the vice president of research at Brown. This project has been ongoing and expanding to include multiple emergency medicine physicians, including a pediatric emergency medicine physicians, medical residents, graduate students in engineering, two undergraduate PLME concentrators, and a pediatric surgeon. The device work supporting the project is from Gregory Crawford’s laboratory. The initial focus of this effort was to develop a technique to noninvasively screen for anemia and detect internal bleeding through diffuse reflectance spectral analysis of the inner eyelid. Since its inception, the initial focus has expanded to include the application of liquid crystals in handheld spectral sensors, application of the same spectral collection principles in laparoscopic procedures to determine local vessel blood constituents and aid in surgical procedures, and a collaborative effort with pediatric emergency medicine to use reflectance spectroscopy for identification of hemoglobin and its metabolitic byproducts in contusions for the purpose of identifying the age of the contusion, important in domestic abuse cases.
