Welcome to the home page of the Paul Braun Research Group at the University of Illinois at Urbana-Champaign. Our group members perform research in the fields of materials chemistry, polymers, biomaterials, organic and inorganic self-assembly, electronic materials and photonics.
New 3D microbatteries stand up to industry standard thin-film counterparts
The thin-film lithium-ion batteries used in microdevices such as portable and medical electronics may supply a good amount of power relative to their mass, but do not provide enough power for many devices due to their limited size. Researchers have introduced a fabrication process that builds microbatteries with thick, 3D electrodes using lithography and electrodeposition – and seals each unit in a gel electrolyte-filled package. The new prototype shows the highest peak power density of any reported microbatteries, the researchers said.
The new study, led by University of Illinois Urbana-Champaign postdoctoral researcher Pengcheng Sun and materials science and engineering professor Paul Braun, is published in the journal Advanced Materials.
Read the full story: https://news.illinois.edu/view/6367/1737488480
Read the full paper: “High-performance packaged 3D lithium-ion microbatteries fabricated using imprint lithography”
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 was 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
| Braun Group Recent Publications |
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| J.G. Kang, H. Jang, J. Ma, Q. Yang, K. Hattar, Z. Diao, R.L. Yuan, J.M. Zuo, S. Sinha, D. Cahill, P. Braun, Ultralow thermal conductivity in nanoporous crystalline Fe3O4, Journal of Physical Chemistry C, 125, 12, 6897-6908 (2021). DOI 10.1021/acs.jpcc.1c00411 |
| Kollarigowda and P.V. Braun, Direct and Divergent Solid-Phase Synthesis of Azobenzene and Spiropyran Derivatives, Journal of Organic Chemistry, 86, 6, 4391-4397 (2021). DOI: 10.1021/acs.joc.0c02375 |
| S. Zeraati, S. Mirkhani, P. Sun, M. Naguib, P.V. Braun and U. Sundararaj, Improved Synthesis of Ti3C2Tx MXene Resulting in Exceptional Electrical Conductivity, High Synthesis Yield, and Enhanced Capacitance, Nanoscale, 13, 3572-3580 (2021). DOI: 10.1039/D0NR06671K |
| T. Yang, P.V. Braun, N. Miljkovic and W.P. King, Phase Change Material Heat Sink for Transient Cooling of High-Power Devices, Journal of Heat and Mass TransferPhase Change Material Heat Sink for Transient Cooling of High-Power Devices, Journal of Heat and Mass Transfer, 170, 121033 (2021). DOI: 10.1016/j.ijheatmasstransfer.2021.121033 |
| Zheng, B. Chen, Y. Xu, N. Fritz, Y. Gurumukhi, J. Cook, M.N. Ates, N. Miljkovic and P.V. Braun, A Gaussian Process-Based Crack Pattern Modeling Approach for Battery Anode Materials Design, Journal of Electrochemical Energy Conversion and Storage, 18, 1, 011011 (2021). DOI: 10.1115/1.4046938 |
| P. Sun, X. Li, J. Shao and P.V. Braun, High‐Performance Packaged 3D Lithium‐Ion Microbatteries Fabricated Using Imprint Lithography, Advanced Materials, 33, 1, 2006229 (2021). DOI: 10.1002/adma.202006229 |
| C.R. Ocier, C.A. Richards, D.A. Bacon-Brown, Q. Ding, R. Kumar, T.J. Garcia, J. van de Groep, J.-H. Song, A.J. Cyphersmith, A. Rhode, A.N. Perry, A.J. Littlefield, J. Zhu, D. Xie, H. Gao, J.F. Messinger, M.L. Brongersma, K.C. Toussaint Jr., L.L. Goddard and P.V. Braun, Direct laser writing of volumetric gradient index lenses and waveguides, Light Science & Applications 9, 196 (2020). DOI: 10.1038/s41377-020-00431-3 |
| S. Kim, B. Lee, J.T. Reeder, S.H. Seo, S.U. Lee, A. Hourlier-Fargette, J. Shin, Y. Sekine, H. Jeong, Y.S. Oh, A.J. Aranyosi, S.P. Lee, J.B. Model, G. Lee, M.H. Seo, S.S. Kwak, S. Jo, G. Park, S. Han, I. Park, H.I. Jung, R. Ghaffari, J. Koo, P.V. Braun, and J.A. Rogers, Soft, skin-interfaced microfluidic systems with integrated immunoassays, fluorometric sensors and impedance measurement capabilities, PNAS, 117, 27906-27915 (2020). DOI: 10.1073/pnas.2012700117 |