Emergent Nanomaterials Lab

The Laboratory for

Emergent Nanomaterials

at The University of Colorado Boulder

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We are an interdisciplinary group of scientists and engineers who think big and build small.


Carson Bruns ,    Director

Carson Bruns, Director

Hyejin Kwon ,  Postdoctoral Associate

Hyejin Kwon, Postdoctoral Associate

Jesse Butterfield ,  PhD Student

Jesse Butterfield, PhD Student

Karan Dikshit ,  PhD Student

Karan Dikshit, PhD Student

Kailey Shara ,  PhD Student

Kailey Shara, PhD Student

Purnendu ,  PhD Student

Purnendu, PhD Student

Sean Keyser ,  MS Student

Sean Keyser, MS Student

Kiley Hartigan ,  Lab Technician

Kiley Hartigan, Lab Technician

Aya Ishikawa ,  Discovery Learning Apprentice

Aya Ishikawa, Discovery Learning Apprentice

Research

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Tech Tattoos

We are re-thinking the tattoo pigment as a way to permanently embed technologies in the skin. We are formulating tattoo inks that conduct electricity and change color in response to different stimuli. We hope to use these "tech tattoos" to power biomedical devices and wearable technologies, monitor and diagnose health issues, and augment human sensing and self-expression.  See our work featured on  CBS News ,  Colorado Pubic Radio ,  KUNC ,  Newsy ,  Daily Mail ,  Inked Magazine , and  CU Boulder Today . Listen to Carson on  The Disruptors podcast . Or watch the TEDx talk on  TED.com :

We are re-thinking the tattoo pigment as a way to permanently embed technologies in the skin. We are formulating tattoo inks that conduct electricity and change color in response to different stimuli. We hope to use these "tech tattoos" to power biomedical devices and wearable technologies, monitor and diagnose health issues, and augment human sensing and self-expression.

See our work featured on CBS News, Colorado Pubic Radio, KUNC, Newsy, Daily Mail, Inked Magazine, and CU Boulder Today. Listen to Carson on The Disruptors podcast. Or watch the TEDx talk on TED.com:

The Mechanical Bond

The mechanical bond is an entanglement in space between component parts that are not otherwise bonded. One example of a system with a mechanical bond is a bead on a string. We thread extremely tiny beads onto extremely tiny strings to create nanomaterials with unusual and potentially functional properties.  Read Carson’s book on  The Nature of the Mechanical Bond .

The mechanical bond is an entanglement in space between component parts that are not otherwise bonded. One example of a system with a mechanical bond is a bead on a string. We thread extremely tiny beads onto extremely tiny strings to create nanomaterials with unusual and potentially functional properties.

Read Carson’s book on The Nature of the Mechanical Bond.

Publications

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  1. Bruns, C. J. The Rise of Smart Tattoos. TEDxMileHigh Blog. 2019.

  2. Sluysmans, D.; Hubert, S.; Bruns, C. J.; Zhu, Z.; Stoddart, J. F.; Duwez, A.-S. Synthetic Oligorotaxanes Exert High Forces When Folding Under Mechanical Load. Nature Nanotech. 2018, 13, 209–213.

  3. Sluysmans, D.; Devaux, F.; Bruns, C. J.; Stoddart, J. F.; Duwez, A.-S. Dynamic Force Spectroscopy of Synthetic Oligorotaxane Foldamers. Proc. Natl. Acad. Sci. U.S.A. 2018, 115, 9362–9366.

  4. Loser, S.; Lou, S. J.; Savoie, B. M.; Bruns, C. J.; Timalsina, A.; Leonardi, M. J.; Harschneck, T.; Turrisi, R.; Zhou, N.; Stern, C. L.; Sarjeant, A. A.; Facchetti, A.; Chang, R. P. H.; Stupp, S. I.; Ratner, M. A.; Chen, L. X.; Marks, T. J. Systematic Evaluation of Structure-Property Relationships in Heteroacene-Diketopyrrolopyrrole Molecular Donors for Organic Solar Cells. J. Mater. Chem. A 2017, 5, 9217–9232.

  5. Slack, C. C.; Finbloom, J. A.; Jeong, K.; Bruns, C. J.; Wemmer, D. B.; Pines, A.; Francis, M. B. Rotaxane Probes for Protease Detection by 129Xe HyperCEST NMR. Chem. Commun. 2017, 53, 1076–1079.

  6. Bruns, C. J.; Liu, H.; Francis, M. B. Near-Quantitative Aqueous Synthesis of Rotaxanes via Bioconjugation to Oligopeptides and Proteins. J. Am. Chem. Soc. 2016, 138, 15307­–15310.

  7. Finbloom, J. A.; Slack, C. C.; Bruns, C. J.; Jeong, K.; Wemmer, D. E.; Pines, A.; Francis, M. B. Rotaxane-Mediated Suppression and Activation of Cucurbit[6]uril for Molecular Detection by 129Xe HyperCEST NMR. Chem. Commun. 2016, 52, 3119–3122.

  8. Aytun, T.; Santos, P. J.; Bruns, C. J.; Huang, D.; Koltonow, A. R.; Olvera de la Cruz, M.; Stupp, S. I. Self-Assembling Tripodal Small-Molecule Donors for Bulk Heterojunction Solar Cells. J. Phys. Chem. C 2016, 120, 3602–3611.

  9. Hou, X.*; Ke, C.*; Bruns, C.; McGonigal, P. R.; Pettman, R. B.; Stoddart, J. F. Tunable Solid-State Fluorescent Materials for Supramolecular Encryption. Nature Commun. 2015, 6, 6884.

  10. Bruns, C. J.*; Fujita, D.*; Hoshino, M.; Sato, S.; Stoddart, J. F.; Fujita, M. Emergent Ion-Gated Binding of Cationic Host-Guest Complexes Within Cationic M12L24 Molecular Flasks. J. Am. Chem. Soc. 2014, 136, 12027–12034

  11. Bruns, C. J.; Stoddart, J. F. Rotaxane-Based Molecular Muscles. Acc. Chem. Res. 2014, 47, 2186–2199.

  12. Bruns, C. J.; Frasconi, M.; Iehl, J.; Hartlieb, K. J.; Schneebeli, S. T.; Cheng, C.; Stupp, S. I.; Stoddart, J. F. Redox Switchable Daisy Chain Rotaxanes Driven by Radical-Radical Interactions. J. Am. Chem. Soc. 2014, 136, 4714–4723. Featured in JACS Spotlights

  13. Bruns, C. J.; Li, J.; Frasconi, M.; Schneebeli, S. T.; Iehl, J.; Jacquot de Rouville, H.-P.; Stupp, S. I.; Voth, G. A.; Stoddart, J. F. An Electrochemically and Thermally Switchable Donor-Acceptor [c2]Daisy Chain Rotaxane. Angew. Chem., Int. Ed. 2014, 53, 1953–1958.

  14. Fahrenbach, A. C.; Bruns, C. J.; Li, H.; Trabolsi, A.; Coskun, A.; Stoddart, J. F. Ground-State Kinetics of Bistable Redox-Active Donor-Acceptor Mechanically Interlocked Molecules. Acc. Chem. Res. 2014, 47, 482–493.

  15. Bruns, C. J.; Stoddart, J. F. Mechanically Interlaced and Interlocked Donor-Acceptor Foldamers. Adv. Polym. Sci. 2013, 261, 271–294.

  16. Bruns, C. J.*; Herman, D. J.*; Minuzzo, J. B.; Lehrman, J. A.; Stupp, S. I. Rationalizing Molecular Design in the Electrodeposition of Anisotropic Lamellar Nanostructures. Chem. Mater. 2013, 25, 4330–4339.

  17. Ruiz-Carretero, A.; Aytun, T.; Bruns, C. J.; Newcomb, C. J.; Tsai, W.-W.; Stupp, S. I. Stepwise Self-Assembly to Improve Solar Cell Morphology. J. Mat. Chem. A 2013, 1, 11674–11681.

  18. Guerrero, A.; Loser, S. C.; Garcia-Belmonte, G.; Bruns, C. J.; Smith, J.; Miyauchi, H.; Stupp, S. I.; Marks, T. J.; Bisquert, J. Solution-Processed Small Molecule: Fullerene Bulk-Heterojunction Solar Cells: Impedance Spectroscopy Deduced Bulk and Interfacial Limits to Fill-Factor. Phys. Chem. Chem. Phys. 2013, 15, 16456–16462.

  19. Juriček, M.*; Barnes, J. C.*; Dale, E. J.; Liu, W.-G.; Strutt, N. L.; Bruns, C. J.; Vermeulen, N. A.; Ghooray, K.; Sarjeant, A. A.; Stern, C. L.; Botros, Y. Y.; Goddard, W. A. III; Stoddart, J. F. Ex2Box: Interdependent Modes of Binding in a Two-Nanometer-Long Synthetic Receptor. J. Am. Chem. Soc. 2013, 135, 12736–12746.

  20. Bruns, C. J.; Stoddart, J. F. Molecular Machines Muscle Up. Nature Nanotechnol. 2013, 8, 9–10.

  21. Zhu, Z.; Bruns, C. J.; Li, H.; Lei, J.; Ke, C.; Liu, Z.; Shafaie, S.; Colquhoun, H. M.; Stoddart, J. F. Synthesis and Solution-State Dynamics of Donor-Acceptor Oligorotaxane Foldamers. Chem. Sci. 2013, 4, 1470–1483.

  22. Barnes, J. C.*; Juriček, M.*; Strutt, N. L.; Frasconi, M.; Sampath, S.; Giesener, M. A.; McGrier, P. L.; Bruns, C. J.; Stern, C. L.; Sarjeant, A. A.; Stoddart, J. F. ExBox: A Polycyclic Aromatic Hydrocarbon Scavenger. J. Am. Chem. Soc. 2013, 135, 183–192.

  23. Bruns, C. J.; Stoddart, J. F. The Mechanical Bond: A Work of Art. Top. Curr. Chem. 2012, 323, 19–72.

  24. Gothard, C. M.*; Bruns, C. J.*; Gothard, N. A.; Grzybowski, B. A.; Stoddart, J. F. Modular Synthesis of Bipyridinium Oligomers and Corresponding Donor-Acceptor Oligorotaxanes with Crown Ethers. Org. Lett. 2012, 14, 5066–5069.

  25. Jacquot de Rouville, H.-P.; Iehl, J.; Bruns, C. J.; McGrier, P. L.; Frasconi, M.; Sarjeant, A. A.; Stoddart, J. F. A Neutral Naphthalene Diimide [2]Rotaxane. Org. Lett. 2012, 14, 5188–5191.

  26. Basuray, A. N.; Jacquot de Rouville, H.-P.; Hartlieb, K. J.; Kikuchi, T.; Strutt, N. L.; Bruns, C. J.; Ambrogio, M. W.; Avestro, A.-J.; Schneebeli, S. T.; Fahrenbach, A. C.; Stoddart, J. F. The Chameleonic Nature of Diazopyrenium Recognition Processes. Angew. Chem., Int. Ed. 2012, 51, 11872–11879.

  27. Fahrenbach, A. C.; Hartlieb, K. J.; Sue, C.-H.; Bruns, C. J.; Barin, G.; Basu, S.; Olson, M. A.; Botros, Y. Y.; Bagabas, A.; Khdary, N.; Stoddart, J. F. Rapid Thermally Assisted Donor-Acceptor Catenation. Chem. Commun. 2012, 48, 9141–9143.

  28. Fahrenbach, A. C.; Bruns, C. J.; Cao, D.; Stoddart, J. F. Ground-State Thermodynamics of Redox-Active Donor-Acceptor Mechanically Interlocked Molecules. Acc. Chem. Res. 2012, 45, 1581–1592.

  29. Loser, S.; Bruns, C. J.; Miyauchi, H.; Ponce Ortiz, R.; Facchetti, A.; Stupp, S. I.; Marks, T. J. A Naphthodithiophene-Diketopyrrolopyrrole Donor Molecule for Efficient Solution-Processed Solar Cells. J. Am. Chem. Soc. 2011, 133, 8142–8145.

  30. Bruns, C. J.; Basu, S.; Stoddart, J. F. Improved Synthesis of 1,5-Dinaphtho[38]Crown-10. Tetrahedron Lett. 2010, 51, 983–986.

  31. Forgan, R. S.; Friedman, D. C.; Stern, C. L.; Bruns, C. J. Stoddart, J. F. Directed Self-Assembly of a Ring-in-Ring Complex. Chem. Commun. 2010, 5861–5863. Front Cover

  32. Boonya-Udtayan, S.; Yotapan, N.; Woo, C.; Bruns, C. J.; Ruchirawat, S.; Thasana, N. Synthesis and Biological Activities of Azalamellarins. Chem. Asian J. 2010, 5, 2113–2123.

Books

 
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REVIEWS

"This book will serve very well to inform any chemist or chemistry student curious as to the workings of molecular topology and the molecular machines that depend upon it, and should be read by anyone seeking to enter these fields. The writing is elegant and at times playful-thoroughly enjoyable to read. This book will certainly occupy pride of place in my research group' library."  Jonathan Nitschke

“… a spectacular book! Many chemists will want to have it on their desks and regard it as the holy writ.” Josef Michl

“The story is told by THE inventor-pioneer-master in the field and is accompanied by amazing illustrations… [it] will become an absolute reference and a best seller in chemistry!” Alberto Credi

“… the great opus on the mechanical bond. A most impressive undertaking!” Jean-Marie Lehn

“I love the first chapter, and its romp through the mechanical bond.” Roald Hoffman

“… what a wonderful read… I thoroughly enjoyed the scientifically atypical perspective. A real pleasure.” Bruce Gibb

“… comprehensive coverage [and] exceptional top-quality graphics… this [is a] definitive book.” Paul Beer

"The Nature of the Mechanical Bond will open new horizons for generations of readers and will stimulate the creativity of many architects of matter who wish to design more and more fascinating molecular systems." Claude Millot

In molecules, the mechanical bond is not shared between atoms—it is a bond that arises when molecular entities become entangled in space. Just as supermolecules are held together by supramolecular interactions, mechanomolecules, such as catenanes and rotaxanes, are maintained by mechanical bonds. This emergent bond endows mechanomolecules with a whole suite of novel properties relating to both form and function. They hold unlimited promise for countless applications, ranging from their presence in molecular devices and electronics to their involvement in remarkably advanced functional materials. The Nature of the Mechanical Bond is a comprehensive review of much of the contemporary literature on the mechanical bond, accessible to newcomers and veterans alike. Topics covered include:
– Supramolecular, covalent, and statistical approaches to the formation of entanglements that underpin mechanical bonds in molecules and macromolecules
– Kinetically and thermodynamically controlled strategies for synthesizing mechanomolecules
– Chemical topology, molecular architectures, polymers, crystals, and materials with mechanical bonds
– The stereochemistry of the mechanical bond (mechanostereochemistry), including the novel types of dynamic and static isomerism and chirality that emerge in mechanomolecules
– Artificial molecular switches and machines based on the large-amplitude translational and rotational motions expressed by suitably designed catenanes and rotaxanes.

This contemporary and highly interdisciplinary field is summarized in a visually appealing, image-driven format, with more than 800 illustrations covering both fundamental and applied research. The Nature of the Mechanical Bond is a must-read for everyone, from students to experienced researchers, with an interest in chemistry’s latest and most non-canonical bond.