Researchers confront optics and data-transfer challenges with 3D-printed lens
Researchers have developed new 3D-printed microlenses with adjustable refractive indices – a property that gives them highly specialized light-focusing abilities. This advancement is poised to improve imaging, computing and communications by significantly increasing the data-routing capability of computer chips and other optical systems, the researchers said.
The study led by University of Illinois Urbana-Champaign researchers Paul Braun and Lynford Goddard and is the first to demonstrate the ability to adjust the direction in which light bends and travels through a lens with sub-micrometer precision.
Read the full story: Researchers confront optics and data-transfer challenges with 3D-printed lens
The results of the study are published in the journal Light: Science and Application: DOI: 10.1038/s41377-020-00431-3
Congratulations to Prof. Paul Braun and Prof. Nancy Sottos!
AAAS Fellows are a distinguished cadre of scientists, engineers and innovators who have been recognized for their achievements across disciplines, from research, teaching, and technology, to administration in academia, industry and government, to excellence in communicating and interpreting science to the public.
Braun as the Guest Editor for the October 2020 MRS Bulletin on Functional Materials and Devices by Self-Assembly.
Dmitri V. Talapin, Michael Engel, Paul V. Braun MRS Bulletin, Volume 45 / Issue 10, October 2020, pp 799 – 806 doi: 10.1557/mrs.2020.252 Published Online on 9 October 2020
Congratulations to Elizabeth Murphy, recipient of the 2020 National Science Foundation (NSF) Graduate Research Fellowship (GRF)! Murphy is a UIUC chemistry student and MRL research assistant with Paul Braun’s group.
“My research interest is developing structure-property relationships in functional polymeric materials,” -Murphy.
Ashish Kulkarni is the recipient of the 2020 Ross J. Martin Award for outstanding research achievement by a graduate student, and recognizes the quality and magnitude of Kulkarni’s research achievements.
Congratulations, Ashish, on this incredible achievement!
Braun led a team that developed a new templating system to help control the quality and unique properties of a special class of inorganic composite materials, including first author, Ashish Kulkarni.
A.A. Kulkarni, E. Hanson, R. Zhang, K. Thornton, and P.V. Braun, Archimedean lattices emerge in template-directed eutectic solidification, Nature, 577, 355-358 (2020). DOI: 10.1038/s41586-019-1893-9
APS Highlight: Ultraviolet Light Makes a Polymer Run Hot or Cold
J. Shin, J. Sung, M. Kang, X. Sie, B. Lee, M.M. Lee, T.J. White, C. Leal, N.R. Sottos, P.V. Braun and D.G Cahill, Light-triggered thermal conductivity switching in azobenzene polymers, PNAS (2019). DOI: 10.1073/pnas.1817082116
Braun research featured in Materials Research Society INTERSECTIONS Issue!
K.A. Miller, E.G. Morado, S.R. Samanta, B.A. Walker, A.Z. Nelson, S. Sen, D.T. Tran, D.J. Whitaker, R.H. Ewoldt, P.V. Braun and S.C. Zimmerman, Acid-Triggered, Acid-Generating, and Self-Amplifying Degradable Polymers, Journal of the American Chemical Society (2019). DOI: 10.1021/jacs.8b07705
M. Ali, T.-H. Tsai and P.V. Braun, Amplified Detection of Chemical Warfare Agents using 2D Chemical Potential Gradients, ACS Omega, 3, 14665-14670 (2018). DOI: 10.1021/acsomega.8b01519
Congratulations to Jungwoo Shin, winner of the Racheff-Intel award (2018)! The award consists of a plaque and up to $1,000 financial support to attend a conference at which the student will present the relevant research.
Jungwoo also received the Dow Chemical Best Presentation Gold Award in Soft Materials (2018) for the combined research presentation with liquid crystal polymer and the azopolymer works.
Story from Kali Serrano: Developing safety leaders at Illinois
H. Zhang, H. Ning, J. Busbee, Z. Shen, C. Kiggins, Y. Huang, J. Eaves, J. Davis, T. Shi, Y.-T. Shao, J.-M. Zuo, X. Hong, Y. Chen, S. Wang, P. Wang, P. Sun, S. Xu, J. Liu, and P.V. Braun, Electroplating Lithium Transition Metal Oxides, Science Advances, 3, e1602427 (2017). DOI: 10.1126/sciadv.1602427
N.A. Krueger, A.L. Holsteen, S.-K. Kang, C. Ocier, W. Zhou, G. Mensing, J.A. Rogers, M.L. Brongersma and P.V. Braun, Porous silicon gradient refractive index micro-optics, Nano Letters, 2016. DOI: 10.1021/acs.nanolett.6b02939
M. T. Barako, A. Sood, C. Zhang, J. Wang, T. Kodama, M. Asheghi, X. Zheng, P.V. Braun, K. Goodson, Quasi-ballistic Electronic Thermal Conduction in Metal Inverse Opals, Nano Letters, 2016. DOI: 10.1021/acs.nanolett.6b00468
10 years in images
Check it out!
Nat. Nanotech. 6, 277–281 (2011)
Nickel inverse opal forms one of the two phases of a battery cathode. Together with an electrochemically active phase, this electrode architecture allows for a rapid ion and electron exchange and transport for fast recharging batteries.
S.-K. Kang, R.KJ. Murphy, S.-W. Hwang, S.M. Lee, D.V. Harburg, N.A. Krueger, J. Shin, P. gamble, H. Cheng, S. Yu, Z. Liu, J.G. McCall, M. Stephens, H. Ying, J. Kim, G. Park, R.C. Webb, C.H. Lee, S. Chung, D.S. Wie, A.D. Gujar, B. Vemulapalli, A.H. Kim, K-M. Lee, J. Cheng, Y. Huang, P.V. Braun, W.Z. Ray and J.A. Rogers, Bioresorbable Silicon Sensors for the Brain with Implantable Wireless Operation, Nature, 530, 71-76 (2016). DOI:10.1038/nature16492
Many news agencies highlight our work on bioresorbable silicon electronic interfaces to the brain, published in Nature; CNN, IEEE Spectrum, Discover, New Scientist, United Press International, Chemical and Engineering News, German Public Radio, and many others, January, 2016.
News-Gazette article featuring Paul Braun – Wired In
Congratulations to former Braun group member Jinyun Liu! His image was selected as a Finalist of the 2016 SCS Science Image Challenge at the University of Illinois!
J. Liu, J. Wang, J. Kim, H. Ning, Z. Pan, S. Kelly, E. Epstein, X.-J. Huang, J. Liu and P.V. Braun, High Full-Electrode Basis Capacity Template-Free Three-Dimensional Nanocomposite Secondary Battery Anodes, Small, 11, 6265-6271 (2015). DOI: 10.1002/smll.201502538
H. Ning, J.H. Pikul, R. Zhang, X. Li, S. Xu, J. Wang, J.A. Rogers, W.P. King and P.V. Braun, Holographic Patterning of High-Performance on Chip 3-D Lithium Ion Batteries, PNAS (2015). DOI: 10.1073/pnas.1423889112
Illinois News Bureau, The Engineer, C&EN plus “News of the Week”, Kurzweilai.net, arstechnica , ECS Blog, Slash Gear, Engineering.com, 3DPrint.com, 3Ders.org, ExtremeTech, NewsKiller, Design Products & Applications, The Register
Congratulations to Braun group undergraduates Nathan Reed and Paige DeGarmo, poster award winners at the East Central Illinois Local ACS Section Undergraduate Research Conference! Nate won the “ECI Local Section Outstanding Poster Award” and Paige won the “Women Chemists Committee Outstanding Poster and Presentation Award.”
J. Kim, L.K. Aagesen, J.H. Choi, J. Choi, H.S. Kim, J. Liu, C.-R. Cho, J.G. Kang, A. Ramazani, K. Thornton and P.V. Braun, Template-Directed Directionally Solidified Three-Dimensionally Mesostructured AgCl-KCl Eutectic Photonic Crystals, Advanced Materials, 27, 4551-4559 (2015). DOI: 10.1002/adma.201502265
C. Zhang, A. Sitt, H.-J. Koo, K. Waynant, H. Hess, B. Pate and P.V. Braun, Autonomic Molecular Transport by Polymers Containing Programmed Chemical Potential Gradients, JACS, 137, 5066-5073 (2015). DOI: 10.1021/jacs.5b00240
C. Zhang, G.G. Cano, P.V. Braun, Linear and Fast Hydrogel Glucose Sensor Materials Enabled by Volume Resetting Agents, Advanced Materials, 26, 5678-5683 (2014). DOI: 10.1002/adma.201401710.
J. Cho, M.D. Losego, H.G. Zhang, H. Kim, J. Zuo, I. Petrov, D.G. Cahill and P.V. Braun, Electrochemically Tunable Thermal Conductivity of Lithium Cobalt Oxide, Nature Communications, 5, 4035 (2014). DOI: 10.1038/ncomms5035
K.A. Arpin, M.D. Losego, A.N. Cloud, H. Ning, J. Mallek, N.P. Sergeant, L. Zhu, Z. Yu, B. Kalanyan, G.N. Parsons, G.S. Girolami, J.R. Abelson, S. Fan and P.V. Braun, Three-Dimensional Self-Assembled Photonic Crystals with High Temperature Stability for Thermal Emission Modification, Nature Communications, 4 (2013). DOI: 10.1038/ncomms3630
J.H. Pikul, H.G. Zhang, J. Cho, P.V. Braun and W. King: High Power Lithium Ion Micro Batteries from Interdigitated Three-Dimensional Bicontinuous Nanoporous Electrodes, Nature Communications, 4, 1732 (2013). DOI: 10.1038/ncomms2747
S. Odom, S. Chayanupatkul, B.J. Blaiszik, O. Zhao, A.C. Jackson, P.V. Braun, N.R. Sottos, S.R. White and J.S. Moore, A Self-Healing Conductive Ink, Advanced Materials, 24, 2578-2581 (2012). DOI: 10.1002/adma.201200196
M. Losego, M.E. Grady, N.R. Sottos, D.G. Cahill and P.V. Braun: Effects of Chemical Bonding on Heat Transport Across Interfaces, Nature Materials, 11, 502-506 (2012). DOI: 10.1038/NMAT3303
S. Cataldo, J. Zhao, F. Neubrech, B. Frank, C. Zhang, P.V. Braun and H. Giessen: Hole-Mask Colloidal Nanolithography for Large-Area Low-Cost Metamaterials and Antenna-Enhanced SEIRA Substrates, ACS Nano, 6, 979-985 (2012). DOI: 10.1021/nn2047982
J. Zhao, C. Zhang, P.V. Braun and H. Giessen, Large-area low-cost Plasmonic nanostructures in the near infrared region for Fano resonant sensing, Advanced Optical Materials, 24, OP247-OP252 (2012). DOI: 10.1002/adma.201202109
Congratulations to Katilin Tyler, recipient of a Mavis Future Faculty Fellowship!
Congratulations to Chunjie Zhang, winner of the Materials Research Society Graduate Student Gold Award for his paper “Hydrogel Sensor Materials for Continuous Glucose Monitoring,” which was presented at the MRS Fall Meeting in Boston, MA.
Press related to Chunjie Zhang’s award (see page 4): http://www.dvidshub.net/publication/issues/14800
Congratulations to James Pikul, winner of the Materials Research Society Graduate Student Gold Award for his paper “High Power Primary Lithium Ion Micro Batteries,” which was presented at the MRS Fall Meeting in Boston, MA.
July 2011, Cover of Nature Materials, Vol. 10
E.C. Nelson, N. Dias, K. Bassett, S. Dunham, V. Verma, M. Miyake, P. Wiltzius, J. Rogers, J. Coleman, X. Li and P.V. Braun: Epitaxial growth of three-dimensionally architectured optoelectronic devices, Nature Materials (2011).
A. Radke, T. Gissibl, T. Klotzbucher, P. V. Braun and H. Giessen: Three-Dimensional Bi-Chiral Plasmonic Crystals Fabricated by Direct Laser Writing and Electroless Silver Plating, Advanced Materials, 23, 3018-3021 (2011). DOI: 10.1002/adma.201100543.
H. Zhang, X. Yu and P.V. Braun: Three-dimensional bicontinuous ultrafast-charge and -discharge bulk battery electrodes, Nature Nanotechnology, 6, 277-281 (2011). DOI: 10.1038/nnano.2011.38 (supplementary information)
Paul Braun is interviewed by the BBC – click to listen!
Podcast with Materials Today – click to listen!
The research on Mechanochemically Active Polymers
(Mechanophores) by Nancy Sottos, Paul Braun, Jeff
Moore and Scott White was featured in the Popular
Science list of “10 Tech Concepts You Need to Know for 2011”
K.A. Arpin, A. Mihi, H.T. Johnson, A.J. Baca, J.A. Rogers, J.A. Lewis and P.V. Braun: Multidimensional Architectures for Functional Optical Devices, Advanced Materials, 22, 1084-1101 (2010). DOI: 10.1002/adma.200904096
SEE THE FORCE: MECHANICAL STRESS LEADS TO SELF-SENSING IN SOLID POLYMERS
Parachute cords, climbing ropes, and smart coatings for bridges that change color when overstressed are several possible uses for force-sensitive polymers being developed by researchers at the University of Illinois.
February 2009, Frontispiece of Advanced Materials, Vol. 21 No.6
Dramatic reduction in corrosion of a steel plate coated with a self-healing coating (right) as compared to a conventional coating is demonstrated. Two samples were scratched and placed in 5% NaCl for 5 days. The background is an optical image (2× magnification), in the foreground is an SEM image of the scratch. In the self-healing sample, the scratch has almost completely self-healed, while in the control sample, the scratch remains all the way down to the substrate.
January 2009, Cover of Advanced Materials, Vol. 21 No.1
Here we report the use of direct laser writing topattern porous 3D structures from photo-responsive colloidal building blocks. Upon 2-photon exposure, the colloids become highly attractive, enabling localized control of aggregation behavior. 3D structures composed of porous walls are harvested by writing intoa colloidal sediment of these particles, followed by rinsing away unexposed colloidal species. Applications may include microfluidics, and studies of porous media, cellular growth and signaling, and colloidal physics. Cover art by Steven Eisenmann of the Beckman Institute VMIL.
January 2008, Cover of Nature Photonics, Vol.2 No.1
Photonic crystals, artificially engineered nanoscale structures that can manipulate the flow of light, show great promise for building sophisticated optical circuitry that can route, filter, store or suppress optical signals. However, fabricating such circuitry presents a great challenge as defects need to be carefully incorporated into the photonic-crystal structure with great precision. Although this has been accomplished for two-dimensional designs that confine light in a plane, it is still an ongoing challenge for so-called complete-bandgap materials, where the defects need to be embedded into a three-dimensional structure. In this issue, Paul Braun and colleagues report the introduction of defects into a silicon three-dimensional photonic crystal by using a technique called two-photon polymerization. The result is waveguides that guide near-infrared light around sharp corners.
Article p52,News & Views p9, UIUC Press Release
Jeong-Ho Park and Paul V. Braun: Coaxial Electrospinning of Self-Healing Coatings, Advanced Materials (2009).
Beckman Institute for Advanced Science and Technology – featuring an article with Paul V. Braun: SYNERGY Fall 2009
Mary M. Caruso, Stuart R. Schelkopf, Aaron C. Jackson, Alexandra M. Landry, Paul V. Braun and Jeffrey S. Moore: Microcapsules Containing Suspensions of Carbon Nanotubes, Journal of Materials Chemistry, 19, 6093 (2009).
Jhy-Tsung Lee, Matthew C. George, Jeffrey S. Moore and Paul V. Braun: Multiphoton Writing of Three-Dimensional Fluidic Channels within a Porous Matrix, Journal of the American Chemical Society (2009).
Soo Hyoun Cho, Scott R. White and Paul V. Braun: Self-Healing Polymer Coatings, Advanced Materials, 21, 645-649 (2009).
tce today, Materials Today, One India, Red Orbit, The Post Chronicle, Thandian News, Times of the Internet, C&EN, UPI.com, Discovery Channel, MRS Bulletin, Eureka, Technology Today, Innovations Report, Illinois News Bureau
Stephanie A. Rinne, Florencio García-Santamaría and Paul V. Braun : Embedded cavities and waveguides in three-dimensional silicon photonic crystals, Nature Photonics, 2, 52-56 (2008).
Beckman Institute researchers, led by Paul Braun and Ben Grosser, receive $1.99 million National Science Foundation MRI award to acquire nano-CT instrument (see press release)
June 2007, Cover of Advanced Materials, Vol. 19, Issue 12
Germanium inverse woodpile 3D photonic crystals with a large (25%) photonic band gap in the infrared (background image) were fabricated through a multistep replication procedure. A polymer scaffold was first created by direct-write assembly, followed by the conformal growth of oxide and semiconductor layers, and removal of the polymer and oxide (foreground), …as reported on p. 1567 by F. García-Santamaría, M. Xu, V. Lousse, S. Fan, P. V. Braun,
and J. A. Lewis.
X. Yu, Y.-J. Lee, R. Furstenberg, J. O. White, and P. V. Braun: Filling Fraction Dependent Properties of Inverse Opal Metallic Photonic Crystals, Advanced Materials, 19, 1689-1692 (2007).
F. García-Santamaría, M. Xu, V. Lousse, S. Fan, P. V. Braun and J. A. Lewis: Germanium Inverse Woodpile Structure with a large photonic band gap, Advanced Materials, 19, 1567-1570, 2007.
May 2007: INVERSE WOODPILE STRUCTURE HAS EXTREMELY LARGE PHOTONIC BAND GAP
Researchers at the U. of I. have built an inverse woodpile structure of germanium, a material with a higher refractive index than silicon.
November 2006, Cover of Advanced Functional Materials, Vol. 16, Issue 17
The direct ink writing of three-dimensional functional materials is detailed in the Feature Article by Lewis on p. 2193. The left side of the cover image displays schematic images that show the conversion of a direct-write polymer woodpile to a silicon hollow-woodpile structure. The 3 × 3 image matrix showcases the resulting silicon photonic crystal (center) surrounded by a higher-magnification view of a representative hollow silicon feature (ca. 1 m in diameter). The figure was prepared by F. Garcia-Santamaria, G. M. Gratson, and P. V. Braun.
The ability to pattern materials in three dimensions is critical for several technological applications, including composites, microfluidics, photonics, and tissue engineering. Direct-write assembly allows one to design and rapidly fabricate materials in complex 3D shapes without the need for expensive tooling, dies, or lithographic masks. Here, recent advances in direct ink writing are reviewed with an emphasis on the push towards finer feature sizes. Opportunities and challenges associated with direct ink writing are also highlighted.
S. H. Cho, S. R. White, and P. V. Braun: Self-healing Polymer Coatings, abstract A3.54, Materials Research Society Fall Meeting, Boston, MA, December 2006.
Z. Ge, Y. Kang, T. A. Taton, P. V. Braun, and D. G. Cahill: Thermal transport in Au-core polymer-shell nanoparticles, Nano Letters, 5, 531-535 (2005).
June 2004, Cover of Langmuir, Vol. 20, Issue 13
Cover illustration by Wonmok Lee and Paul V. Braun showing to the left a scanning electron microscope image of a substrate patterned with a periodic array of dimples formed through focused ion beam lithography and to the right a laser scanning confocal microscope cross section of a 3-D colloidal crystal formed by gravity-driven sedimentation from a binary mixture of 1.18 m diameter colloidal microspheres and 6 nm diameter highly charged nanoparticles onto this patterned substrate. After microsphere settling, the nanoparticle solution surrounding the colloidal crystal was gelled in situ by introducing ammonia vapor, which increased the pH and enabled drying with minimal microsphere rearrangement. The confocal image shown here was generated by infilling the dried colloidal crystal with an index-matched fluorescent dye solution prior to imaging. These colloidal crystals have very low defect densities and may be suitable for use as photonic crystals and as templates for photonic band gap materials. The dimple pitch and the volume fraction of microspheres in solution were found to strongly impact the quality of the resulting colloidal crystal. For more information see “Nanoparticle-Mediated Epitaxial Assembly of Colloidal Crystals on Patterned Substrates” by Wonmok Lee, Angel Chan, Michael A. Bevan, Jennifer A. Lewis, and Paul V. Braun on pages 5262-5270 of this issue. Copyright 2004 American Chemical Society
H. Liang, T. E. Angelini, J.Ho, P. V. Braun and G. C. L. Wong: Molecular imprinting of biomineralized CdS nanostructures: Crystallographic control using self-assembled DNA-membrane templates, Journal of the American Chemical Society, 125, 11786-11787 (2003).
W. Lee, S. A. Pruzinsky, and P. V. Braun: Multi-photon polymerization of waveguide structures within three-dimensional photonic crystals, Advanced Materials, 14, 271-274 (2002).