@article{13351,
  abstract     = {Molecular recognition is at the heart of the noncovalent synthesis of supramolecular assemblies and, at higher length scales, supramolecular materials. In a recent publication in Nature, Stoddart and co-workers demonstrate that the formation of host-guest complexes can be catalyzed by one of the simplest possible catalysts: the electron.},
  author       = {Gemen, Julius and Klajn, Rafal},
  issn         = {2451-9294},
  journal      = {Chem},
  keywords     = {Materials Chemistry, Biochemistry (medical), General Chemical Engineering, Environmental Chemistry, Biochemistry, General Chemistry},
  number       = {5},
  pages        = {1183--1186},
  publisher    = {Elsevier},
  title        = {{Electron catalysis expands the supramolecular chemist’s toolbox}},
  doi          = {10.1016/j.chempr.2022.04.022},
  volume       = {8},
  year         = {2022},
}

@article{13352,
  abstract     = {Optoelectronic effects differentiating absorption of right and left circularly polarized photons in thin films of chiral materials are typically prohibitively small for their direct photocurrent observation. Chiral metasurfaces increase the electronic sensitivity to circular polarization, but their out-of-plane architecture entails manufacturing and performance trade-offs. Here, we show that nanoporous thin films of chiral nanoparticles enable high sensitivity to circular polarization due to light-induced polarization-dependent ion accumulation at nanoparticle interfaces. Self-assembled multilayers of gold nanoparticles modified with L-phenylalanine generate a photocurrent under right-handed circularly polarized light as high as 2.41 times higher than under left-handed circularly polarized light. The strong plasmonic coupling between the multiple nanoparticles producing planar chiroplasmonic modes facilitates the ejection of electrons, whose entrapment at the membrane–electrolyte interface is promoted by a thick layer of enantiopure phenylalanine. Demonstrated detection of light ellipticity with equal sensitivity at all incident angles mimics phenomenological aspects of polarization vision in marine animals. The simplicity of self-assembly and sensitivity of polarization detection found in optoionic membranes opens the door to a family of miniaturized fluidic devices for chiral photonics.},
  author       = {Cai, Jiarong and Zhang, Wei and Xu, Liguang and Hao, Changlong and Ma, Wei and Sun, Maozhong and Wu, Xiaoling and Qin, Xian and Colombari, Felippe Mariano and de Moura, André Farias and Xu, Jiahui and Silva, Mariana Cristina and Carneiro-Neto, Evaldo Batista and Gomes, Weverson Rodrigues and Vallée, Renaud A. L. and Pereira, Ernesto Chaves and Liu, Xiaogang and Xu, Chuanlai and Klajn, Rafal and Kotov, Nicholas A. and Kuang, Hua},
  issn         = {1748-3395},
  journal      = {Nature Nanotechnology},
  keywords     = {Electrical and Electronic Engineering, Condensed Matter Physics, General Materials Science, Biomedical Engineering, Atomic and Molecular Physics, and Optics, Bioengineering},
  number       = {4},
  pages        = {408--416},
  publisher    = {Springer Nature},
  title        = {{Polarization-sensitive optoionic membranes from chiral plasmonic nanoparticles}},
  doi          = {10.1038/s41565-022-01079-3},
  volume       = {17},
  year         = {2022},
}

@article{13353,
  abstract     = {We show that the optical properties of indigo carmine can be modulated by encapsulation within a coordination cage. Depending on the host/guest molar ratio, the cage can predominantly encapsulate either one or two dye molecules. The 1 : 1 complex is fluorescent, unique for an indigo dye in an aqueous solution. We have also found that binding two dye molecules stabilizes a previously unknown conformation of the cage.},
  author       = {Yanshyna, Oksana and Avram, Liat and Shimon, Linda J. W. and Klajn, Rafal},
  issn         = {1364-548X},
  journal      = {Chemical Communications},
  keywords     = {Materials Chemistry, Metals and Alloys, Surfaces, Coatings and Films, General Chemistry, Ceramics and Composites, Electronic, Optical and Magnetic Materials, Catalysis},
  number       = {21},
  pages        = {3461--3464},
  publisher    = {Royal Society of Chemistry},
  title        = {{Coexistence of 1:1 and 2:1 inclusion complexes of indigo carmine}},
  doi          = {10.1039/d1cc07081a},
  volume       = {58},
  year         = {2022},
}

@article{13355,
  abstract     = {Supramolecular self-assembly in biological systems holds promise to convert and amplify disease-specific signals to physical or mechanical signals that can direct cell fate. However, it remains challenging to design physiologically stable self-assembling systems that demonstrate tunable and predictable behavior. Here, the use of zwitterionic tetrapeptide modalities to direct nanoparticle assembly under physiological conditions is reported. The self-assembly of gold nanoparticles can be activated by enzymatic unveiling of surface-bound zwitterionic tetrapeptides through matrix metalloprotease-9 (MMP-9), which is overexpressed by cancer cells. This robust nanoparticle assembly is achieved by multivalent, self-complementary interactions of the zwitterionic tetrapeptides. In cancer cells that overexpress MMP-9, the nanoparticle assembly process occurs near the cell membrane and causes size-induced selection of cellular uptake mechanism, resulting in diminished cell growth. The enzyme responsiveness, and therefore, indirectly, the uptake route of the system can be programmed by customizing the peptide sequence: a simple inversion of the two amino acids at the cleavage site completely inactivates the enzyme responsiveness, self-assembly, and consequently changes the endocytic pathway. This robust self-complementary, zwitterionic peptide design demonstrates the use of enzyme-activated electrostatic side-chain patterns as powerful and customizable peptide modalities to program nanoparticle self-assembly and alter cellular response in biological context.},
  author       = {Huang, Richard H. and Nayeem, Nazia and He, Ye and Morales, Jorge and Graham, Duncan and Klajn, Rafal and Contel, Maria and O'Brien, Stephen and Ulijn, Rein V.},
  issn         = {1521-4095},
  journal      = {Advanced Materials},
  keywords     = {Mechanical Engineering, Mechanics of Materials, General Materials Science},
  number       = {1},
  publisher    = {Wiley},
  title        = {{Self‐complementary zwitterionic peptides direct nanoparticle assembly and enable enzymatic selection of endocytic pathways}},
  doi          = {10.1002/adma.202104962},
  volume       = {34},
  year         = {2022},
}

@article{21078,
  abstract     = {The ease with which racemic mixtures crystallize compared with the equivalent chiral systems is routinely taken advantage of to produce crystals of small molecules. However, biological macromolecules such as DNA and proteins are naturally chiral, and thus the limited range of chiral space groups available hampers the crystallization of such molecules. Inspiring work over the past 15 years has shown that racemic mixtures of proteins, which were made possible by impressive advances in protein chemical synthesis, can indeed improve the success rate of protein crystallization experiments. More recently, the racemic crystallization approach was extended to include nucleic acids as a possible aid in the determination of enantiopure DNA crystal structures. Here, findings are reported that suggest that the benefits may extend beyond this. Two racemic crystal structures of the DNA sequence d(CCCGGG) are described which were found to fold into A-form DNA. This form differs from the Z-form DNA conformation adopted by the chiral equivalent in the solid state, suggesting that the use of racemates may also favour the emergence of new conformations. Importantly, the racemic mixture forms interactions in the solid state that differ from the chiral equivalent (including the formation of racemic pseudo-helices), suggesting that the use of racemic DNA mixtures could provide new possibilities for the design of precise self-assembled nanomaterials and nanostructures.},
  author       = {Mandal, Pradeep K and Collie, Gavin W. and Kauffmann, Brice and Huc, Ivan},
  issn         = {2059-7983},
  journal      = {Acta Crystallographica Section D Structural Biology},
  number       = {6},
  pages        = {709--715},
  publisher    = {International Union of Crystallography},
  title        = {{Racemic crystal structures of A-DNA duplexes}},
  doi          = {10.1107/s2059798322003928},
  volume       = {78},
  year         = {2022},
}

@article{21079,
  abstract     = {<jats:title>Abstract</jats:title><jats:p>A series of aromatic oligoamide foldamer sequences containing different proportions of three δ‐amino acids derived from quinoline, pyridine, and benzene and possessing varying flexibility, for example due to methylene bridges, were synthesized. Crystallographic structures of two key sequences and <jats:sup>1</jats:sup>H NMR data in water concur to show that a canonical aromatic helix fold prevails in almost all cases and that helix stability critically depends on the ratio between rigid and flexible units. Notwithstanding subtle variations of curvature, i. e. the numbers of units per turn, the aromatic δ‐peptide helix is therefore shown to be general and tolerant of a great number of sp<jats:sup>3</jats:sup> centers. We also demonstrate canonical helical folding upon alternating two monomers that do not promote folding when taken separately: folding occurs with two methylenes between every other unit, not with one methylene between every unit. These findings highlight that a fine‐tuning of helix handedness inversion kinetics, curvature, and side chain positioning in aromatic δ‐peptidic foldamers can be realized by systematically combining different yet compatible δ‐amino acids.</jats:p>},
  author       = {Bindl, Daniel and Mandal, Pradeep K and Huc, Ivan},
  issn         = {1521-3765},
  journal      = {Chemistry – A European Journal},
  number       = {31},
  publisher    = {Wiley},
  title        = {{Generalizing the aromatic δ‐amino acid foldamer helix}},
  doi          = {10.1002/chem.202200538},
  volume       = {28},
  year         = {2022},
}

@article{21080,
  abstract     = {Tight binding was observed between the C‐terminal cross section of aromatic oligoamide helices in aqueous solution, leading to the formation of discrete head‐to‐head dimers in slow exchange on the NMR timescale with the corresponding monomers. The nature and structure of the dimers was evidenced by 2D NOESY and DOSY spectroscopy, mass spectrometry and X‐ray crystallography. The binding interface involves a large hydrophobic aromatic surface and hydrogen bonding. Dimerization requires that helices have the same handedness and the presence of a C‐terminal carboxy function. The protonation state of the carboxy group plays a crucial role, resulting in pH dependence of the association. Dimerization is also influenced by neighboring side chains and can be programmed to selectively produce heteromeric aggregates.},
  author       = {Bindl, Daniel and Mandal, Pradeep K and Allmendinger, Lars and Huc, Ivan},
  issn         = {1521-3773},
  journal      = {Angewandte Chemie International Edition},
  number       = {11},
  publisher    = {Wiley},
  title        = {{Discrete stacked dimers of aromatic oligoamide helices}},
  doi          = {10.1002/anie.202116509},
  volume       = {61},
  year         = {2022},
}

@article{21527,
  abstract     = {Optical metasurfaces have been heralded as the platform to integrate multiple functionalities in a compact form-factor, with the potential to replace bulky optical components. A central stepping stone toward realizing this promise is the demonstration of multifunctionality under several constraints (e.g., at multiple incident wavelengths and/or angles) in a single device, an achievement being hampered by design limitations inherent to single-layer planar geometries. Here, we propose a framework for the inverse design of multilayer metaoptics via topology optimization, showing that even few-wavelength thick devices can achieve high-efficiency multifunctionality, such as multiangle light concentration and plan-achromaticity. We embody our framework in multiple closely spaced patterned layers of a low-index polymer, with fabrication constraints specific to this platform enforced in the optimization process. We experimentally demonstrate our approach with an inverse-designed 3D-printed light concentrator working at five different nonparaxial angles of incidence. Our framework paves the way toward realizing multifunctional ultracompact 3D nanophotonic devices.},
  author       = {Roques-Carmes, Charles and Lin, Zin and Christiansen, Rasmus E. and Salamin, Yannick and Kooi, Steven E. and Joannopoulos, John D. and Johnson, Steven G. and Soljačić, Marin},
  issn         = {2330-4022},
  journal      = {ACS Photonics},
  keywords     = {metasurfaces, inverse design, multilayered metaoptics, 3D printing, topology optimization},
  number       = {1},
  pages        = {43--51},
  publisher    = {American Chemical Society},
  title        = {{Toward 3D-printed inverse-designed metaoptics}},
  doi          = {10.1021/acsphotonics.1c01442},
  volume       = {9},
  year         = {2022},
}

@article{21584,
  abstract     = {Bombardment of materials by high-energy particles often leads to light emission in a process known as scintillation. Scintillation has widespread applications in medical imaging, x-ray nondestructive inspection, electron microscopy, and high-energy particle detectors. Most research focuses on finding materials with brighter, faster, and more controlled scintillation. We developed a unified theory of nanophotonic scintillators that accounts for the key aspects of scintillation: energy loss by high-energy particles, and light emission by non-equilibrium electrons in nanostructured optical systems. We then devised an approach based on integrating nanophotonic structures into scintillators to enhance their emission, obtaining nearly an order-of-magnitude enhancement in both electron-induced and x-ray–induced scintillation. Our framework should enable the development of a new class of brighter, faster, and higher-resolution scintillators with tailored and optimized performance.},
  author       = {Roques-Carmes, Charles and Rivera, Nicholas and Ghorashi, Ali and Kooi, Steven E. and Yang, Yi and Lin, Zin and Beroz, Justin and Massuda, Aviram and Sloan, Jamison and Romeo, Nicolas and Yu, Yang and Joannopoulos, John D. and Kaminer, Ido and Johnson, Steven G. and Soljačić, Marin},
  issn         = {1095-9203},
  journal      = {Science},
  number       = {6583},
  publisher    = {American Association for the Advancement of Science},
  title        = {{A framework for scintillation in nanophotonics}},
  doi          = {10.1126/science.abm9293},
  volume       = {375},
  year         = {2022},
}

@inproceedings{21590,
  abstract     = {We introduce end-to-end inverse design in which a nanophotonics frontend is optimized in conjunction with a computational-imaging backend to minimize reconstruction errors. We present several nanophotonics designs for depth, spectral and polarization imaging.},
  author       = {Lin, Zin and Arya, Gaurav and Li, William F. and Roques-Carmes, Charles and Pestourie, Raphaël and Li, Zhaoyi and Capasso, Federico and Soljačić, Marin and Johnson, Steven G.},
  booktitle    = {Conference on Lasers and Electro-Optics},
  location     = {San Jose, CA, United States},
  publisher    = {Optica Publishing Group},
  title        = {{End-to-end nanophotonics inverse design for computational imaging}},
  doi          = {10.1364/cleo_at.2022.jw5q.1},
  year         = {2022},
}

@inproceedings{21591,
  abstract     = {We present a method for angle and wavelength sensing for underdetermined imaging systems by performing end-to-end nanophotonic inverse design with a compressed sensing backend.},
  author       = {Li, William F. and Arya, Gaurav and Roques-Carmes, Charles and Lin, Zin and Johnson, Steven G. and Soljačić, Marin},
  booktitle    = {Conference on Lasers and Electro-Optics},
  location     = {San Jose, CA, United States},
  publisher    = {Optica Publishing Group},
  title        = {{Angular and spectral sparse sensing with end-to-end optimized nanophotonics}},
  doi          = {10.1364/cleo_at.2022.jw5q.2},
  year         = {2022},
}

@inproceedings{21624,
  abstract     = {We show in both theory and experiment that flatband photonic resonances can control and boost free-electron radiation, as validated by enhancement, band, and polarization-shaping measurements.},
  author       = {Yang, Yi and Roques-Carmes, Charles and Kooi, Steven E. and Tang, Haoning and Beroz, Justin and Mazur, Eric and Kaminer, Ido and Joannopoulos, John D. and Soljačić, Marin},
  booktitle    = {Conference on Lasers and Electro-Optics},
  location     = {San Jose, CA, United States},
  publisher    = {Optica Publishing Group},
  title        = {{Enhanced Smith–Purcell radiation from photonic flatband resonances}},
  doi          = {10.1364/cleo_qels.2022.ff2c.7},
  year         = {2022},
}

@inproceedings{21625,
  abstract     = {We demonstrate how Implosion Fabrication, a new three-dimensional nanofabrication technique, enables the realization of three-dimensional photonic devices at optical wavelengths. We realize two- and three-dimensional optical crystals of hydrogel-embedded silver meta-atoms.},
  author       = {Salamin, Yannick and Mills, Brian and Yang, Gaojie and Yang, Quansan and Swain, Corban and Oran, Daniel and Sloan, Jamison and Roques-Carmes, Charles and Beroz, Justin and Kooi, Steven E. and Boyden, Edward S. and Soljačić, Marin},
  booktitle    = {Conference on Lasers and Electro-Optics},
  location     = {San Jose, CA, United States},
  publisher    = {Optica Publishing Group},
  title        = {{Three-dimensional optical crystals nanoprinted in a hydrogel}},
  doi          = {10.1364/cleo_qels.2022.ff2d.1},
  year         = {2022},
}

@inproceedings{21628,
  abstract     = {We develop a general framework to enhance and control X-ray scintillation by embedding nanophotonic structures into scintillators. We demonstrate 10-fold scintillation enhancement in a conventional scintillator, showing the potential of our technique for X-ray imaging.},
  author       = {Roques-Carmes, Charles and Rivera, Nicholas and Kooi, Steven E. and Yu, Yang and Joannopoulos, John D. and Kaminer, Ido and Soljačić, Marin},
  booktitle    = {Conference on Lasers and Electro-Optics},
  location     = {San Jose, CA, United States},
  publisher    = {Optica Publishing Group},
  title        = {{X-ray imaging with nanophotonic scintillators}},
  doi          = {10.1364/cleo_si.2022.sm3k.1},
  year         = {2022},
}

@article{21638,
  abstract     = {We introduce end-to-end inverse design for multi-channel imaging, in which a nanophotonic frontend is optimized in conjunction with an image-processing backend to extract depth, spectral and polarization channels from a single monochrome image. Unlike diffractive optics, we show that subwavelength-scale “metasurface” designs can easily distinguish similar wavelength and polarization inputs. The proposed technique integrates a single-layer metasurface frontend with an efficient Tikhonov reconstruction backend, without any additional optics except a grayscale sensor. Our method yields multi-channel imaging by spontaneous demultiplexing: the metaoptics front-end separates different channels into distinct spatial domains whose locations on the sensor are optimally discovered by the inverse-design algorithm. We present large-area metasurface designs, compatible with standard lithography, for multi-spectral imaging, depth-spectral imaging, and “all-in-one” spectro-polarimetric-depth imaging with robust reconstruction performance (≲ 10% error with 1% detector noise). In contrast to neural networks, our framework is physically interpretable and does not require large training sets. It can be used to reconstruct arbitrary three-dimensional scenes with full multi-wavelength spectra and polarization textures.},
  author       = {Lin, Zin and Pestourie, Raphaël and Roques-Carmes, Charles and Li, Zhaoyi and Capasso, Federico and Soljačić, Marin and Johnson, Steven G.},
  issn         = {1094-4087},
  journal      = {Optics Express},
  number       = {16},
  pages        = {28358--28370},
  publisher    = {Optica Publishing Group},
  title        = {{End-to-end metasurface inverse design for single-shot multi-channel imaging}},
  doi          = {10.1364/oe.449985},
  volume       = {30},
  year         = {2022},
}

@unpublished{21673,
  abstract     = {When impinging on optical structures or passing in their vicinity, free electrons can spontaneously emit electromagnetic radiation, a phenomenon generally known as cathodoluminescence. Free-electron radiation comes in many guises: Cherenkov, transition, and Smith-Purcell radiation, but also electron scintillation, commonly referred to as incoherent cathodoluminescence. While those effects have been at the heart of many fundamental discoveries and technological developments in high-energy physics in the past century, their recent demonstration in photonic and nanophotonic systems has attracted a lot of attention. Those developments arose from predictions that exploit nanophotonics for novel radiation regimes, now becoming accessible thanks to advances in nanofabrication. In general, the proper design of nanophotonic structures can enable shaping, control, and enhancement of free-electron radiation, for any of the above-mentioned effects. Free-electron radiation in nanophotonics opens the way to promising applications, such as widely-tunable integrated light sources from x-ray to THz frequencies, miniaturized particle accelerators, and highly sensitive high-energy particle detectors. Here, we review the emerging field of free-electron radiation in nanophotonics. We first present a general, unified framework to describe free-electron light-matter interaction in arbitrary nanophotonic systems. We then show how this framework sheds light on the physical underpinnings of many methods in the field used to control and enhance free-electron radiation. Namely, the framework points to the central role played by the photonic eigenmodes in controlling the output properties of free-electron radiation (e.g., frequency, directionality, and polarization). [... see full abstract in paper]},
  author       = {Roques-Carmes, Charles and Kooi, Steven E. and Yang, Yi and Rivera, Nicholas and Keathley, Phillip D. and Joannopoulos, John D. and Johnson, Steven G. and Kaminer, Ido and Berggren, Karl K. and Soljačić, Marin},
  booktitle    = {arXiv},
  title        = {{Free-electron-light interactions in nanophotonics}},
  doi          = {10.48550/arXiv.2208.02368},
  year         = {2022},
}

@article{21809,
  abstract     = {Controlling the multistage photoresponsivity remains a challenge, in part, due to the spontaneous tautomerization between isomers. Herein, we present a strategy to access three independent states (linear, cyclic keto, and cyclic enolate) of crown ether (CE)-substituted donor–acceptor Stenhouse adducts (DASAs) by limiting the tautomerization of the closed isomers. The linear–cyclic keto isomerization is reversibly triggered by treatment with metal ions (Na+ or K+) and CE, while the linear–cyclic enolate isomerization is induced by green light and heat. Density functional theory and molecular dynamics calculation results suggest that the steric effect and supramolecular interaction between the electron-donating and electron-withdrawing moieties play an important role in hindering the tautomerization between cyclic keto and cyclic enolate DASA-CE. The strategy to influence key steps in the photoswitching process inspires well-controlled multistage isomerization of photoresponsive molecules.},
  author       = {Duan, Yongli and Zhao, Haiquan and Xue, Guodong and Sun, Fanxi and Stricker, Friedrich J and Wang, Zhen and Mao, Lijun and He, Chao and de Alaniz, Javier Read and Zheng, Yonghao and Wang, Dongsheng},
  issn         = {1520-5207},
  journal      = {The Journal of Physical Chemistry B},
  number       = {17},
  pages        = {3347--3354},
  publisher    = {American Chemical Society},
  title        = {{Controlling the isomerization of photoresponsive molecules through a limiting tautomerization strategy}},
  doi          = {10.1021/acs.jpcb.2c02005},
  volume       = {126},
  year         = {2022},
}

@article{21819,
  abstract     = {The ability of molecular photoswitches to convert on/off responses into large macroscale property change is fundamental to light-responsive materials. However, moving beyond simple binary responses necessitates the introduction of new elements that control the chemistry of the photoswitching process at the molecular scale. To achieve this goal, we designed, synthesized and developed a single photochrome, based on a modified donor–acceptor Stenhouse adduct (DASA), capable of independently addressing multiple molecular states. The multi-stage photoswitch enables complex switching phenomena. To demonstrate this, we show spatial control of the transformation of a three-stage photoswitch by tuning the population of intermediates along the multi-step reaction pathway of the DASAs without interfering with either the first or final stage. This allows for a photonic three-stage logic gate where the secondary wavelength solely negates the input of the primary wavelength. These results provide a new strategy to move beyond traditional on/off binary photochromic systems and enable the design of future molecular logic systems.},
  author       = {Stricker, Friedrich J and Sanchez, David M. and Raucci, Umberto and Dolinski, Neil D. and Zayas, Manuel S. and Meisner, Jan and Hawker, Craig. J. and Martínez, Todd. J. and Read de Alaniz, Javier},
  issn         = {1755-4349},
  journal      = {Nature Chemistry},
  pages        = {942--948},
  publisher    = {Springer Nature},
  title        = {{A multi-stage single photochrome system for controlled photoswitching responses}},
  doi          = {10.1038/s41557-022-00947-8},
  volume       = {14},
  year         = {2022},
}

@article{21823,
  abstract     = {DFT calculations were used to find an optimal substitution site on the triene backbone of a donor–acceptor Stenhouse adduct photoswitch to tune the equillibrium and switching kinetics of DASA without modifying the donor and acceptor groups. Using this approach we demonstrate a new means to tuning DASA based photoswitches by increasing the energy of the closed form relative to the open form. To highlight the potential of this approach a new DASA derivative bearing a methyl substituent on the 5-position of the triene was synthesized and the effect of this substitution was studied using 1H NMR spectroscopy, time-dependent UV-Vis and solvatochromic analysis. The new DASA derivative shows a higher dark equillibrium, favoring the open form, and drastically faster thermal recovery than the unsubstituted derivative with the same donor and acceptor.},
  author       = {Peterson, Julie A. and Stricker, Friedrich J and Read de Alaniz, Javier},
  issn         = {1364-548X},
  journal      = {Chemical Communications},
  number       = {14},
  pages        = {2303--2306},
  publisher    = {Royal Society of Chemistry},
  title        = {{Improving the kinetics and dark equilibrium of donor-acceptor Stenhouse adduct by triene backbone design}},
  doi          = {10.1039/d1cc06235b},
  volume       = {58},
  year         = {2022},
}

@article{21824,
  abstract     = {We investigate the influence of the host matrix on the photothermally driven actuation performance of negatively photochromic, donor−acceptor Stenhouse adduct (DASA)-based polymers. Using a modular Diels−Alder “click” platform, we designed polymeric materials with varying DASA incorporation and investigated the relationships between the material composition and the resulting physical, mechanical, and photoswitching properties. We demonstrate that increasing the DASA concentration in polymer conjugates has a dramatic effect on the material’s physical and mechanical properties, such as the glass transition temperature (Tg) and elastic modulus, as well as the photoswitching properties, which are found to be highly dependent on Tg. We establish using a simple photoresponsive bilayer that actuation performance is controlled by the bilayer stiffness rather than the photochrome incorporation of DASA. Finally, we report and compare the light-induced property changes in Tg and the elastic modulus between the materials comprising the open or closed forms of DASAs. Our results demonstrate the importance of designing a material that is stiff enough to provide the mechanical strength required for actuation under load, but soft enough to reversibly switch at the operational temperature and provide key considerations for the development of application-geared photoswitchable materials.},
  author       = {Sroda, Miranda M. and Lee, Jaejun and Kwon, Younghoon and Stricker, Friedrich J and Park, Minwook and Valentine, Megan T. and Read de Alaniz, Javier},
  issn         = {2637-6105},
  journal      = {ACS Applied Polymer Materials},
  keywords     = {donor−acceptor Stenhouse adducts, photothermal actuation, photo-induced property changes, negative photochromism, glass transition temperature},
  number       = {1},
  pages        = {141--149},
  publisher    = {American Chemical Society},
  title        = {{Role of material composition in photothermal actuation of DASA-based polymers}},
  doi          = {10.1021/acsapm.1c01108},
  volume       = {4},
  year         = {2022},
}