Combining Structural Topology Optimization and Big Area Additive Manufacturing – A Case Study

Nik Nikolov is an Assistant Professor of Art, Architecture and Design at Lehigh University.

This research project investigated the problems, workflow, and feasibility of designing a small topologically optimized structure and its fabrication in polymer-extruding large area 3d printer. Topology optimization (TO) as an architectural design tool is largely unexplored, in contrast to its wide use in the field of mechanical engineering. As big area additive manufacturing (BAAM) finally enters the realm of full-scale single-build structural design, research like the one proposed holds a significant potential for design innovation in addressing structural expression in buildings of varying scales.

The work was presented at the ACSA Fall Conference: Between the Autonomous & Contingent Object, October 8-10, 2015 at Syracuse University, Syracuse, NY and was accepted for journal publication and presentation at the 2016 International Conference on Structures and Architecture June 19-21, Guimaraes, Portugal. Additionally the work was part of a NSF grant application (Directorate of Engineering, PD 15-1637, proposal title “Development of Binder Jet 3D Printing of Concrete Components for Structural and Architectural Applications”) with prof Clay Naito, co PI.


Using computation to understand noise production and reduction

Justin Jaworski and Keith Moored are Co-PIs and both Assistant Professors of Mechanical Engineering and Mechanics at Lehigh University. They were assisted by graduate student Nathan Wagenhoffer. Below they discusses their research on  how noise is created. 

Aerodynamic noise generation is important to many engineering applications, such as wind turbines and aircraft, where noise annoyance to the public is critical.  Excessive noise explains in part why most airports are located well outside of city limits and major highways are flanked by traffic noise barriers; people don’t like noise. The generation of noise is found by analyzing how the air or fluid around objects is disturbed. For our purposes, we identify noise generation in two broad senses: scattered noise and radiated noise. Scattered noise results from a sound wave encounters a solid body and is amplified and bounces off. Radiated noise is made by vibratory motion of the body. If we can find a way to model acoustic disturbances in air, for example, then we can find how these motions can generate noise.  In a concerted effort to identify the noise from arbitrary solid bodies, we have developed a two-dimensional (2D) acoustic field solver. The 2D model allows us to simplify problems to their essentials, while still ascertaining where and how the noise is generated for a specific body. We simply need to define how does the pressure around a body behaves and then a resulting acoustic field can be found.

But finding the pressure field around an airfoil, for instance, is not a straightforward task. To accurately find the pressure on a moving airfoil, one actually has to solve the equations of fluid flow for the body. We choose to describe our fluids problem with the similar mathematical treatment as the acoustics section. This allows for us to use the same to perform the analysis on the exact same geometry and exploit any speed up algorithms on both problems.   The fluid solver finds how the airfoil makes vorticity, or local spinning of a region of fluid, due to its movement. Vorticity is responsible for most sound generated created at low speeds, so a coupling of this flow solver with the acoustic solver is natural. The motion of a vortex, a coherent region of vorticity, produces a greater pressure than its surrounding area.
Continue reading Using computation to understand noise production and reduction

Studying hot Stars with disks

All stars are not created equal. When you look out into the night sky, you are seeing all sorts of unique and interesting objects. Some stars are small and cool (at least, compared to our Sun), and live for many billions of years. Others have evolved and inflated to enormous sizes- even over 1,000 times the size of our sun. There is a class of bright, blue stars called “Classical Be stars” that are between about 5 – 20 times more massive than the sun, and spin so quickly that they are nearly torn apart by the resulting centrifugal force. These stars also have disks that grow and shrink, appear and disappear. Classical Be stars are unique in astronomy, because their disks originate from the stars themselves. Material from the surface of the star is flung outward with so much speed (and angular momentum) that it is launched into orbit, and then settles into a disk in an event called an “outburst”. Lehigh physics professor Joshua Pepper and graduate student Jonathan Labadie-Bartz are studying these objects because there is still much that is unknown, especially regarding the physical mechanisms behind outbursts. The header image shows an artist’s rendition of a Be star and its disk.

Continue reading Studying hot Stars with disks

Natural Feature Localization Robotics Technology for Warehouse Environments

John Spletzer is an Associate Professor of Computer Science and Engineering at Lehigh University. Below he details the 

The inspiration for this project came during my sabbatical at Love Park Robotics, LLC (LPR) in 2015. LPR is a robotics startup doing work in industrial perception, and the primary project I worked on was a vision-based pallet detection system for use by Automated Guided Vehicles (AGVs). AGVs are autonomous vehicles operating in warehouse environments. Think “robot forklift,” and you have the right idea. To estimate their position and orientation, AGVs typically rely upon 2D LIDAR (laser scanner) based localization systems that track reflector targets surveyed into the warehouse. The approach is very effective, and can provide sub-centimeter levels of accuracy. However, the process of installing the targets is both time consuming and expensive. Furthermore, it needs to be repeated any time the warehouse is reconfigured. Conversations with Tom Panzarella, CEO of LPR, lead us to investigate an alternative approach. Our hypothesis was that recent advances in 3D LIDAR systems would allow us to estimate AGV pose by tracking natural features already existing in the warehouse. This would eliminate the need for retroreflector targets all together. We refer to this technology as AGV-3D. From my NSF CAREER research, my lab had already demonstrated that a smart wheelchair system using a similar approach could reliably navigate in an urban environment without GPS. You can see an early video from the project here:

Continue reading Natural Feature Localization Robotics Technology for Warehouse Environments

Hot Water in the Arctic: Oases for Life Beneath Ice-Covered Oceans

Jill McDermott is an Assistant Professor in the Department of Earth and Environmental Sciences at Lehigh University.  Her research is taking her to the high Arctic to explore for new volcanic activity and ecosystems on the seafloor.  Follow along live on the cruise blog

NASA’s mission to the ice-covered ocean of Jupiter’s moon Europa will launch in the 2020s. About a decade from today the first data return may arrive, but in the meantime there is plenty to do on our own planet. This week, I join a rare mission on the German icebreaker Polarstern to do the next best thing – a search for submarine hydrothermal vents in the Arctic Ocean.  Our goal is to reveal the chemical signatures that accompany life on the seafloor, and track these signals upward through the ocean water to the overlying ice-water interface, and into the ice itself.  The idea is to discover an extreme ecosystem living below the Arctic ice to understand how to design a mission for a future space lander. This well-informed lander will make similar measurements while looking for life on Europa’s icy surface.

At 87°N 61°E in the Arctic, two of Earth’s tectonic plates diverge along an underwater volcanic mountain chain called the Gakkel Ridge, which stretches for 1,100 miles off Greenland towards Siberia. The plate motion here is the slowest in the world, spreading apart only 0.4 inches per year, at a rate 3 times slower than your fingernails grow. Due to this low tectonic activity, it seemed unlikely that the Gakkel would host hydrothermal vents – places where seawater circulating through fractures in the seafloor rock extracts heat derived from volcanic activity, and rises up to the seafloor in scalding plumes of mineral-laden water. These vents deliver chemicals to the seafloor that provide energy and building materials for specialized ecosystems, a process called ‘chemosynthesis.’ In 2003, however, a team of shocked scientists discovered chemical signatures in the water indicating multiple regions of hydrothermal activity along the Gakkel Ridge.

All scientific research requires patient dedication, and this expedition builds on years of risks, set-backs, and successes of many colleagues. The deep ocean is harsh. The freezing waters of the Arctic are even less forgiving than the mid-latitudes, and little is known about the seafloor ecosystems that are living there, undetected for tens of millions of years. In the coming weeks, I may be among the fortunate few to collect the first samples at the seafloor at one of the Gakkel vent sites.

We are aiming for a particular location in the Arctic, the Karasik Massif, an underwater mountain that rises rapidly from 15,400 feet depth to 1,850 feet depth. The Karasik Massif lies along a fault, a break in the seafloor rock that cuts through thin ocean crust into underlying ‘ultramafic’ rocks that formed deeper in Earth’s mantle.

The ultramafic geologic setting makes this site an exciting target for exploration due to the geochemistry that arises when circulating fluids interact with iron-rich rocks at high Lost City Hydrothermal Fieldtemperatures and pressures. Similar conditions exist at two other known hydrothermal fields in the Atlantic Ocean, Lost City and Rainbow, where vent fluids expelled at the seafloor are rich in dissolved hydrogen gas.  The enrichment in hydrogen gas means there is great potential for the chemical, or ‘abiotic’ formation of organic molecules like methane and formic acid – possible precursors to the prebiotic compounds from which life on Earth emerged. There are only a few well-characterized seafloor ultramafic vent sites, however, and every one is different. This expedition is vital to understand the full range of chemical and biological diversity possible around Earth’s chemosynthetic ecosystems.

One challenge to studying the chemistry of modern vent fluids is that living things now permeate our planet. Organic compounds can also be generated and consumed by life itself, of course, and active microbial communities living in the seafloor around the vents rely on chemical energy from compounds emitted by the vents, such as hydrogen and methane. My goal on this expedition is to collect vent fluids and characterize their geochemistry, including distinguishing abiotic from biotic chemical processes, and how these influence the generation of life-related biogeochemical signatures.

To collect the vent fluids, we will launch the Nereid Under-Ice, a new remotely operated underwater vehicle developed and operated by the Woods Hole Oceanographic Institution . The Nereid UI will first be deployed in free-swimming autonomous mode to make high-resolution seafloor maps and track down the vents by measuring chemical clues, such as particle-rich water and locations where the seawater is relatively rich in hydrogen and methane. Once the exact location of the vent site is known, the Nereid UI will transform and launch again, now tethered by a fiberoptic cable the width of a human hair.  I will equip it with titantium syringes that can collect vent fluid samples and maintain seafloor pressures until the samples are back onboard the ship. There my colleagues and I will begin the exciting task of understanding the origin of these fluids, how they sustain life on the Arctic seafloor, and what this means for life detection on other planetary bodies in our solar system and beyond.

Research support includes funding from the National Aeoronautics and Space Administration and the Alfred-Wegener Institute.

Image credits:

Research icebreaker Polarstern: Mario Hoppmann, Alfred Wegener Institute

Mosaic of the Lost City Hydrothermal Field: D. Kelley, University of Washington

Nereid Under-Ice rendering:  Woods Hole Oceanographic Institution








Tracing James and Du Bois in Berlin

Saladin Ambar is the Department Chair and an Associate Professor in the Department of Political Science at Lehigh University. His research recently took him to Germany to track the work of William James and W.E.B. Du Bois
On May 22nd I arrived in Berlin, Germany to begin research funded by a Lehigh Faculty Innovation Grant. I was there to investigate the influence of German education on the thinking and political thought of both Harvard University’s William James, and his then student, W.E.B. Du Bois, the first African American to graduate from that institution withIMG_0781 a PhD. In addition to seeking out the archives at Humboldt University (formerly the University of Berlin), I was also asked to present my research to a group of graduate students at the University of Potsdam. At the invitation of Professor Logi Gunnarsson, an expert on James’s work, I was able to share the influence of James’s teaching on the young Du Bois, as we navigated James’s 1890 text “The Hidden Self.” The dialogue and feedback was wonderful. And I made an invaluable friend and colleague in Logi. We often forget how influential German intellectuals were in shaping the American academy. James and Du Bois were no different. It was truly exciting to be in this formerly divided city, thinking about race, the subconscious mind, and double consciousness, all with young men and women eager to complete their own graduate education and share their perspectives on a topic that clearly crosses the Atlantic in terms of importance. I look forward to returning to Cambridge to learn more about James and Du Bois at Harvard – but also one day to Berlin – and to Potsdam – to revisit the same field of study that so shaped these two critical thinkers in American race and psychology.

Developing a vertebrate model system for Roberts Syndrome

Kathy Iovine, an Associate Professor in the Department of Biological Sciences, and Bob Skibbens, a Professor in the Department of Biological Sciences, introduce you to their research on Roberts Syndrome. This work is funded in part by a Faculty Innovation Grant

Greetings! The purpose of this post is to introduce you to a Faculty Innovation Grant titled Developing a vertebrate model system for Roberts Syndrome. Roberts Syndrome (RBS) is a severe form of birth defects that significantly impacts bone growth (as well as cognition and organ development).  In RBS patients, the long bones of the limbs are severely reduced, along with craniofacial abnormalities (cleft palatte, small head size, etc). The syndrome arises due to mutations in a gene named ESCO2, but the basis of the ESCO2 defect remains unknown.  An important step forward will be to develop a model system for RBS so that we can ultimately devise clinical therapies.

As part of a collaboration between the Skibbens and Iovine lab groups, we are establishing the zebrafish fin as an RBS model system.  Zebrafish fins are an excellent system since amputation results in complete regrowth, and we have the technology to turn down gene function during regrowth (“regeneration”).  We found that loss of Esco2 protein causes skeletal defects in  the zebrafish regenerating fin (Figure 1 shows a normal fin skeleton). With the ability to assay for Esco2 function in regenerating fins, we are pursuing a new model that Esco2 may cause skeletal defects by regulating the expression of genes.  Evidence obtained through this collaboration suggests that Esco2 regulates cs43 – a gene that encodes a protein previously shown by the Iovine lab to impact bone growth (check out Iovine et al., 2005, Developmental Biology) and implicated in a developmental abnormality referred to as Oculodentodigital dysplasia.  This research has been published in the journal Developmental Dynamics (Banerji et al., 2016 Developmental Dynamics)!

More recent efforts have been to provide mechanistic insights into how Esco2 regulates the expression of the skeletal gene cx43. The most direct way to show this is to demonstrate that the Esco2 protein, or a protein regulated by the function of Esco2 (i.e. Smc3), associates with the cx43 gene. Esco2 regulates the ability of Smc3 (and others) to associate with DNA. We are now testing if Smc3 physically binds to the DNA surrounging the cx43 gene. Raj Banerji has made important progress showing that she can isolate chromatin (i.e. genomic DNA plus all of the associated proteins) from a fin cell line, AB9. She can also isolate only the parts of the chromatin that are associated with Smc3. She is now testing if cx43 DNA is among the isolated Smc3-bound chromatin.


Keywords: skeletal disease, zebrafish, regeneration, gene expression


Resources for proposal writing

Proposal development is a regular facet of faculty life, but it is one that isn’t necessarily included in graduate training. Fortunately there are plenty of resources available to help. Below is a round up of some of the best online guides.

  • The Foundation Center has a short online course laying out the components of a typical grant application and provides tips for writer.
  • For NEH applicants, OSU posted slides and a video  of a workshop with Claudia Kinkela, NEH program officer.
  • The Social Science Research Council website includes a free publication On the Art of Writing Proposals.
  • Applicants should also begin by looking for specific advice from the foundation or federal agency to which they are applying.

All of these resources share some of the same specific advice: write for the educated generalist. Good luck!

The Research Lifecycle: Seeing it Through and Starting Anew

Jenna Lay is Associate Professor and Director of Graduate Studies in the English Department of Lehigh University. 

The academic lifecycle is an unusual one. Years unfold in months-long stretches of time: fall and spring semesters devoted to teaching and running academic programs; summer, as Nicholas Sawicki suggests in his post, offering time for larger projects, writing, and travel—like the archival work Elizabeth Dolan describes. The rhythm of an academic career offers similar ebbs and flows, as the boisterous conversation of graduate coursework transforms into the solitary discipline of a dissertation, which, in turn, enables the intellectual growth that will foster new forms of engagement in the classroom and in a broad range of communities.

As a pre-tenure faculty member at Lehigh, I spent the last six years building on that foundation: transforming the knowledge and skills gained through graduate study into the research, teaching, and service that structure academic days, months, and years. I can now hold the most material of these transformations in my hands: my first book, Beyond the Cloister: Catholic Englishwomen and Early Modern Literary Culture, was published this month by the University of Pennsylvania Press.

With my book’s publication, I’ve been thinking about the research lifecycle, and especially about how scholars transition from one project to the next. Watching my words evolve from malleable files on my computer to the relative fixity of a printed book, I’ve become increasingly convinced that a research project is never truly complete: that the questions answered will inevitably spark new ideas and areas for exploration. And yet this is still a summer of endings and beginnings, of one project completed and another just developing. In this blog post, I’ll say a bit about what a transitional period like this entails: what did my summers look like when I was working on Beyond the Cloister? How does this summer differ?

Continue reading The Research Lifecycle: Seeing it Through and Starting Anew

A new project: dating the chronology of European migration

David Anastasio is a geologist in the Department of Earth and Environmental Studies at Lehigh University. He is currently blogging from his research site in Spain. Catch up here!

A persistent debate surrounds the chronology of the colonization of Europe. The Guadix-Baza Basin in southern Spain is the repository of 2,000 m of ancient sedimentary strata that record the depositional, climatic, ecological, and tectonic events along the European-African plate boundary at a time of hominin migration out of Africa. The basin was also the


lake beds where a 1.4Ma hominid tooth (pictured) was discovered site of the last connection between the Atlantic Ocean and Mediterranean Sea before the modern connection at Gibraltar. Retreat of the seaway resulted in the largest lake in Europe, which evolved from grassland environments to a savannah landscape with abundant game. Previous studies have established the paleoenviromental evolution of the archeological sites but without precise chronologies it is not possible to reconcile arguments as to whether evolving climactic or geographic barriers in the Betic Cordillera were instrumental in facilitating the peopling of Europe or whether hominins simply “followed the herd”.

Josep Parés (Spanish Research Center for Human Evolution) and I are using the record of periodic changes in Earth’s orbital parameters (Milankovitch cycles) that are encoded in nearly all sedimentary rocks to refine chronologies. Orbital cycles are known to result in natural long-term variations in Earth’s climate. When tuned to absolute time control, cyclostratigraphy constitutes a metronome with a precision, accuracy, and continuity that out performs other dating methods. Our sampling strategy will allow the basin’s paleoarcheology sites to be more precisely dated and correlated so that coordinated paleogeographic and paleoenvironmental parameters can be established.

Skip to toolbar