Researchers from the 91̽�� have discovered a new way to help liquid flow in only one direction — but without flaps. In a published Sept. 24 in the Proceedings of the National Academy of Sciences, they report that a flexible pipe — with an interior helical structure inspired by shark intestines — can keep fluid flowing in one direction without the flaps that engines and anatomy rely upon.

Human intestines are essentially a hollow tube. But for sharks and rays, their intestines feature a network of spirals surrounding an interior passageway. In a 2021 , a different team proposed that this unique structure promoted one-way flow of fluids — also known as flow asymmetry — through the digestive tracts of sharks and rays without flaps or other aids to prevent backup. That claim caught the attention of 91̽��postdoctoral researcher , lead author on the new paper.

“Flow asymmetry in a pipe with no moving flaps has tremendous technological potential, but the mechanism was puzzling,” says Levin. “It was not clear which parts of the shark’s intestinal structure contributed to the asymmetry and which served only to increase the surface area for nutrient uptake.”

To answer these questions, Levin led a team that included co-authors and , both 91̽��professors of chemistry, and Naroa Sadaba, a fellow 91̽��postdoctoral researcher. They 3D-printed a series of “biomimetic pipes,” all with interior helices inspired by the layout of shark intestines. They varied the geometrical parameters among these prototype pipes, such as the pitch angle of the helix or the number of turns. Their first pipes were printed from rigid materials, and they found that some showed a strong preference for unidirectional flow.

“The first measurement of flow asymmetry was a ‘Eureka’ moment,” said Levin. “Until that instant, we didn’t know if our idealized structures could reproduce the flow effects seen in sharks.”

By further tuning the geometrical parameters and printing new designs, the researchers increased the flow asymmetry until it rivaled and even exceeded designs of famed inventor Nikola Tesla, who more than a century ago the Tesla valve, a with no moving parts.

“You don’t get to beat Tesla every day!” said Levin.

But shark intestines — like human intestines — aren’t rigid. The team suspected that so-called “deformable structures,” which are made from more flexible materials, might perform even better as Tesla valves. They 3D-printed a second series of prototypes made from the softest polymer that is both printable and commercially available. These flexible pipe designs, which are better mimics for shark intestines through both their “deformability” and their interior helices, performed at least seven times better compared to all previously measured Tesla valves.

“Chemists were already motivated to develop polymers that are simultaneously soft, strong and printable,” said Nelson, an expert in developing new types of polymers. “The potential use of these polymers to control flow in applications ranging from engineering to medicine strengthens that motivation.”

“Actual intestines are still about 100 times softer than our soft material, so there is plenty of room for improvement,” said Sadaba.

Keller credits the project’s success to the team’s interdisciplinary ideas from biology, chemistry and physics, and to the sharks themselves.

“Biomimicry is a powerful way of discovering new designs,” said Keller. “We never would have thought of the structures ourselves.”

The research was funded by the National Science Foundation, the Washington Research Foundation and the Fulbright Foundation.

For more information, contact Keller at slkeller@uw.edu, Nelson at alshakim@uw.edu and Levin at idolevin@uw.edu.

Twenty scientists and engineers at the 91̽�� are among the 38 new members elected to the Washington State Academy of Sciences for 2021, according to a July 15 . New members were chosen for “their outstanding record of scientific and technical achievement, and their willingness to work on behalf of the Academy to bring the best available science to bear on issues within the state of Washington.”

Current academy members selected 29 of the new members. An additional nine were elected by virtue of joining one of the National Academies.

New 91̽��members who were elected by current academy members are:

• , professor and Port of Tacoma Chair in Environmental Science at 91̽��Tacoma, director of the and science director of the , “for foundational work on the environmental fate, behavior and toxicity of PCBs.”
• , professor of psychology, “for contributions in research on racial and gender inequality that has influenced practices in education, government, and business” and “for shifting the explanation for inequality away from individual deficiencies and examining how societal stereotypes and structures cause inequalities.”
• , professor of chemistry and member faculty at the , “for leadership in the innovative synthesis and chemical modification of nanoscale materials for application in light emission and catalysis.”
• , professor of global health and of environmental and occupational health sciences, and founding director of the , “for work on the health impacts of climate change, on climate impact forecasting, on adaptation to climate change and on climate policy to protect health.”
• , professor of environmental and forest sciences and dean emeritus of the College of the Environment, “for foundational studies of regional paleoenvironmental history and sustained excellence in academic leadership to catalyze and sustain transformative research and educational initiatives.” Graumlich is also president-elect of the American Geophysical Union.
• Dr. , the Joseph W. Eschbach Endowed Chair in Kidney Research and co-director of the , “for pioneering contributions and outstanding achievements in the development of the novel wearable artificial kidney, as well as numerous investigator-initiated clinical trials and multi-center collaborative studies.”
• , professor of environmental chemistry and chair of the Physical Sciences Division at 91̽��Bothell, “for leadership in monitoring and understanding the global transport of atmospheric pollutants from energy production, wildfire, and other sources, as well as science communication and service that has informed citizens and enhanced public policy.”
• , professor and chair of psychology, “for contributions demonstrating how psychological science can inform long-standing issues about racial and gender discrimination” and “for research that has deep and penetrating implications for the law and societal efforts to remedy social inequities with evidence-based programs and actions.”
• , the Leon C. Johnson Professor of Chemistry, member faculty at the and chair of the Department of Chemistry, “for developing new spectroscopy tools for measuring energy flow in molecules and materials with high spatial and temporal resolution.”
• , professor of astronomy, “for founding the and leading the decades-long development of the interdisciplinary modeling framework and community needed to establish the science of exoplanet astrobiology” and “for training the next generation of interdisciplinary scientists who will search for life beyond Earth.”
• , professor and chair of aeronautics and astronautics, “for leadership and significant advances in nonlinear methods for integrated sensing and control in engineered, bioinspired and biological flight systems” and “for leadership in cross-disciplinary aerospace workforce development.”
• , associate professor of chemistry and member faculty with the Molecular Engineering and Sciences Institute, “for exceptional contributions to the development of synthetic polymers and nanomaterials for self-assembly and advanced manufacturing with application in sustainability, medicine and microelectronics.”
• Dr. , Associate Dean of Medical Technology Innovation in the College of Engineering and the School of Medicine, the Graham and Brenda Siddall Endowed Chair in Cornea Research, and medical director of the 91̽��Eye Institute, “for developing and providing first class clinical treatment of severe corneal blindness to hundreds of people, for establishing the world premier artificial cornea program in Washington, and for leading collaborative research to translate innovative engineering technologies into creative clinical solution.”
• Dr. , professor of medicine and director of the , “for global recognition as an authority on drug and vaccine development for viral and parasitic diseases through work as an infectious disease physician and immunologist.”
• Dr. , professor of pediatrics and of anesthesiology and pain medicine, and director of the , “for outstanding leadership in pediatric anesthesiology and in the care of children with traumatic brain injury” and “for internationally recognized expertise in traumatic brain injury and direction of the Harborview Injury Prevention and Research Center for the last decade as an exceptional mentor and visionary leader.”

91̽��members who will join the Washington State Academy of Sciences by virtue of their election to one of the National Academies are:

• , professor of biostatistics, “for the development of novel statistical models for longitudinal data to better diagnose disease, track its trajectory, and predict its outcomes” and “for revolutionizing how dynamic predictors are judged by their discrimination and calibration and has significantly advanced methods for randomized controlled trials.” Heagerty was elected to the National Academy of Medicine in 2021.
• , the Bill and Melinda Gates Chair in Computer Science and Engineering, “for foundational contributions to the mathematics of computer systems and of the internet, as well as to the design and probabilistic analysis of algorithms, especially on-line algorithms, and algorithmic mechanism design and game theory.” Karlin was elected to the National Academy of Sciences in 2021.
• , professor emeritus of applied mathematics and data science fellow at the , “for inventing key algorithms for hyperbolic conservation laws and transforming them into powerful numerical technologies” and “for creating the Clawpack package, which underpins a wide range of application codes in everyday use, such as for hazard assessment due to tsunamis and other geophysical phenomena.” LeVeque was elected to the National Academy of Sciences in 2021.
• , the Benjamin D. Hall Endowed Chair in Basic Life Sciences and an investigator with the Howard Hughes Medical Institute, “for advancing our physical understanding of cell motility and growth in animals and bacteria” and “for discovering how the pathogen Listeria uses actin polymerization to move inside human cells, how crawling animal cells coordinate actomyosin dynamics and the mechanical basis of size control and daughter cell separation in bacteria.” Theriot was elected to the National Academy of Sciences in 2021.
• , professor and chair of biological structure, “for elucidating cellular transformations through which neurons pattern their dendrites, and the interplay of activity-dependent and -independent mechanisms leading to assembly of stereotyped circuits” and “for revelations regarding the fundamental principles of neuronal development through the application of an elegant combination of in vivo imaging, physiology, ultrastructure and genetics to the vertebrate retina.” Wong was elected to the National Academy of Sciences in 2021.

New members to the Washington State Academy of Sciences are scheduled to be inducted at a meeting in September.

Several honors, grant awards in 2020 for Nadya Peek of HCDE

, 91̽��assistant professor of human centered design and engineering, received an honor in 2020 as well as several research grants. MIT Review in June named her to its annual list of , celebrating those whose work “has the greatest potential to transform the world.”

Peek leads the UW’s , a research group that uses machine precision to assist human creativity, and co-directs the .

In recent months, Peek received a from the Alfred P. Sloan Foundation to study testing and verification of quality control strategies for manufactured products responding to the COVID-19 pandemic. She and a University of California colleague also were awarded a two-year National Science Foundation to research digital manufacturing tools for low-volume manufacturing.

Peek is a co-principal investigator on a $2 million, three-year grant from the NSF’s Emerging Frontiers in Research and Innovation Program, announced in October, to develop distributed chemical manufacturing using synthetic biology. 91̽��chemical engineering professor is the project lead, along with 91̽��chemistry assistant professor and chemical engineering associate professor .

Also, Peek and , professor in the Paul G. Allen School of Computer Science & Engineering, will share a three-year NSF to develop open source, customizable “co-bots,” or collaborative robots designed to work alongside humans in scientific work as well as other fields such as advanced fabrication and quality control.

Read more at Peeks’ page on the Department of Human Centered Design & Engineering .

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Miranda Belarde-Lewis a new iSchool endowed faculty fellow

, assistant professor in the 91̽��Information School, has been named the inaugural .

Belarde-Lewis (Zuni/Tlingit) is an independent curator as well as a professor of North American Indigenous Knowledge with the iSchool, and her work examines the role of social media in protecting, perpetuating and documenting Native American information and knowledge.

The award comes with funds Belarde-Lewis can use to apply for grants, bring speakers to campus and the community, or help with her research.

is the former longtime director of the UW’s Odegaard Undergraduate Library and was the iSchool’s Distinguished Alumna for 2020.

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American Political Science Association honors Aseem Prakash

, 91̽��professor of political science, has received the 2020 from the American Political Science Association’s Science, Technology and Environmental Politics division.

(1933-2012) was a well-known American political scientist, who received the Nobel Memorial Prize in Economic Sciences. Prakash, who knew Ostrom and her husband well, is the Walker Family Professor for the Arts and Sciences and directs the UW-based . The award was announced in the summer.

A team of chemical engineers has developed a new way to produce medicines and chemicals and preserve them using portable “biofactories” embedded in water-based gels known as hydrogels. The approach could help people in remote villages or on military missions, where the absence of pharmacies, doctor’s offices or even basic refrigeration makes it hard to access critical medicines and other small-molecule compounds.

The team — led by , a professor of chemical engineering at the University of Texas, and , an assistant professor of chemistry at the 91̽�� — describes the new approach in a published Feb. 4 in Nature Communications.

“We expect these developments to afford new technologies for on-demand production of small-molecule and peptide products in the future,” said Nelson, who is also a faculty member in the 91̽��, in a accompanying the paper. “This technology will be especially applicable in remote or isolated areas where space and resources are limited, which could include manned space missions or personalized medications.”

Their system effectively embeds microbial biofactories — cells engineered to overproduce a product — into the solid scaffold of a hydrogel, allowing for portability and optimized production. It is the first hydrogel-based system to organize both individual microbes and consortia for in-the-moment production of high-value chemical feedstocks, used for processes such as fuel and pharmaceutical production. Products can be produced within a couple of hours to a couple of days.

“Many of the chemicals, fuels, nutraceuticals and pharmaceuticals we use rely on traditional fermentation technology,” said Alper. “Our technology addresses a strong limitation in the fields of synthetic biology and bioprocessing, namely the ability to provide a means for both on-demand and repeated-use production of chemicals and antibiotics from both mono- and co-cultures.”

As a crosslinked polymer, the hydrogel used in this work can be 3D printed or manually extruded. The gel material, along with the cells inside, can flow like a liquid and then harden upon exposure to UV light. The resulting polymer network is large enough for molecules and proteins to move through it, but the space is too small for cells to leak out.

The team also found that by freeze-drying the hydrogel system, it can effectively preserve the fermentation capacity of the biofactories until needed in the future. The result of the freeze-drying somewhat resembles an ancient mummy, shriveled up but well-preserved. To revive the hydrogel, the researchers simply added water, sugar and other basic nutrients, and the cells could resume production just as effectively as before the preservation process.

One of the novel applications enabled by this platform is the ability to combine multiple different organisms, called consortia, together in a way that outperforms traditional, large-scale bioreactors. In particular, this system enables a plug-and-play approach to combining and optimizing chemical production. For example, if one set of enzymes works best in the bacteria E. coli, while the other works best in budding yeast, the two organisms can work together to more efficiently go straight to the product. The research team tested both of these organisms.

This platform has the added benefit of multitasking, keeping different types of cells separated while they grow, preventing one from taking over and killing off the others. Likewise, by testing a range of temperatures, the team could control the dynamics of the system, keeping the growth of multiple cell types balanced.

Finally, the team showed continuous, repeated use of the system — with yeast cells — over the course of an entire year without a decrease in yields, indicating the sustainability of the process over time.

Medicines such as antibiotics have a fixed shelf life and require specific storage conditions. The portability of a biofactory that can synthesize these molecules makes the hydrogel system especially useful in remote places that don’t have access to refrigeration to store medications. It would also be a small and compact way to maintain access to several medications and other essential chemicals when there is no access to a pharmacy or a store, like during a military mission or a mission to Mars. Although not quite there yet, the possibilities are promising.

“This technology can be applied to a wide range of products and cell types. We see engineers and scientists being able to plug and play with different consortia of cells to produce diverse products that are needed for a specific scenario,” Alper said. “That’s part of what makes this technology so exciting.”

Co-lead authors on the paper are 91̽��graduate student Trevor Johnston and University of Texas graduate student Shuo-Fu Yuan. Co-authors are James Wagner and Xiunan Yi at the University of Texas, former 91̽��postdoctoral researcher Abhijit Saha, and 91̽��graduate student Patrick Smith. The research was funded by the Camille and Henry Dreyfus Foundation, the 91̽�� and the Royalty Research Fund.

For more information contact Nelson at alshakim@uw.edu.

Adapted from a by the University of Texas news office.