Microfibers composed of azobenzene-based photochromic amorphous molecular materials, namely low molecular-mass photochromic materials with a glass-forming property, could be fabricated. These fibers were found to exhibit mechanical bending motion upon irradiation with a laser beam. In addition, the bending direction could be controlled by altering the polarization direction of the irradiated light without changing the position of the light source or the wavelength of the light. In-situ fluorescence observation of mass transport induced at the surface of the fiber doped with CdSe quantum dots suggested that the bending motions were related with the photoinduced mass transport taking place near the irradiated surface of the fiber.
References
[1]
Welker, D.J.; Kuzyk, M.J. Photomechanical stabilization in polymer fiber-based all-optical circuit. Appl. Phys. Lett. 1994, 64, 809–811, doi:10.1063/1.111021.
Yu, Y.; Nakano, M.; Ikeda, T. Directed bending of a polymer film by light. Nature 2003, 425, doi:10.1038/425145a.
[4]
Camacho-Lopez, M.; Finkelmann, H.; Palffy-Muhoray, P.; Shelley, M. Fast liquid-crystal elastomer swims into the dark. Nat. Mater. 2004, 3, 307–310, doi:10.1038/nmat1118.
[5]
Kondo, M.; Yu, Y.; Ikeda, T. How does the initial alignment of mesogens affect the photoinduced bending behavior of liquid-crystalline elastomers? Angew. Chem. Int. Ed. 2006, 45, 1378–1382, doi:10.1002/anie.200503684.
[6]
Bian, S.; Robinson, D.; Kuzyk, M.G. Optically activated cantilever using photomechanical effects in dye-soped polymer fibers. J. Opt. Soc. Am. B 2006, 23, 697–708, doi:10.1364/JOSAB.23.000697.
[7]
Corbett, D.; Warner, M. Linear and nonlinear photoinduced deformations of cantilevers. Phys. Rev. Lett. 2007, 99, doi:10.1103/PhysRevLett.99.174302.
[8]
van Oosten, C.L.; Bastiaansen, C.W.M.; Broer, D.J. Printed artificial cilia from liquid-crystal network actuatos modularly driven by light. Nat. Mater. 2009, 8, 677–682, doi:10.1038/nmat2487.
[9]
Choi, H.J.; Jeong, K.-U.; Chien, L.-C.; Lee, M.-H. Photochromic 3-dimensional actuator based on an uncrosslinked liquid crystal elastomer. J. Mater. Chem. 2009, 19, 7124–7129.
[10]
Dawson, N.J.; Kuzyk, M.G.; Neal, J.; Luchette, P.; Palffy-Muhoray, P. Experimental studies of the mechanicsms of photomechanical effects in a nematic liquid crystal elastomer. J. Opt. Soc. Am. B 2011, 28, 1916–1921, doi:10.1364/JOSAB.28.001916.
[11]
Dawson, N.J.; Kuzyk, M.G., Neal; Luchette, P.; Paffy-Muhoray, P. Modeling the mechanisms of the photomechanical response of a nematic liquid crystal elastomer. J. Opt. Soc. Am. B 2011, 28, 2134–2141, doi:10.1364/JOSAB.28.002134.
[12]
Kobatake, S.; Takami, S.; Muto, H.; Ishikawa, T.; Irie, M. Rapid and reversible shape changes of molecular crystals on photoirradiation. Nature 2007, 446, 778–781, doi:10.1038/nature05669.
Koshima, H.; Ojima, N.; Uchimoto, H. Mechanical motion of azobenzene crystals upon photoirradiation. J. Am. Chem. Soc. 2009, 131, 6890–6891, doi:10.1021/ja8098596.
[15]
Shirota, Y.; Moriwaki, K.; Yoshikawa, S.; Ujike, T.; Nakano, H. 4-[Di(biphenyl-4-yl)amino]-azobenzene and 4,4'-Bis[bis(4'-tert-butylbiphenyl-4-yl)amino]azobenzene as a Novel Family of Photochromic Amorphous Molecular Materials. J. Mater. Chem. 1998, 8, 2579–2581, doi:10.1039/a806802j.
[16]
Utsumi, H.; Nagahama, D.; Nakano, H.; Shirota, Y. A Novel Family of Photochromic Amorphous Molecular Materials Based on Dithienylethene. J. Mater. Chem. 2000, 10, 2436–2437, doi:10.1039/b005067i.
[17]
Utsumi, H.; Nagahama, D.; Nakano, H.; Shirota, Y. Synthesis of a Novel Family of Photochromic Amorphous Molecular Materials Based on Dithienylethene, and Their Photochromic Properties and Application for Dual Image Formation. J. Mater. Chem. 2002, 12, 2612–2619, doi:10.1039/b205201f.
[18]
Tanino, T.; Yoshikawa, S.; Ujike, T.; Nagahama, D.; Moriwaki, K.; Takahashi, T.; Kotani, Y.; Nakano, H.; Shirota, Y. Creation of Azobenzene based Photochromic Amorphous Molecular Materials—Synthesis, Glass-forming Properties, and Photochromic Response. J. Mater. Chem. 2007, 17, 4953–4963.
[19]
Nagahama, D.; Nakano, H.; Shirota, Y. Synthesis and Photochromic Response of a New Photochromic Amorphous Molecular Material Based on Spirooxazine. J. Photopolym. Sci. Tech. 2008, 21, 755–757, doi:10.2494/photopolymer.21.755.
[20]
Nakano, H.; Takahashi, T.; Kadota, T.; Shirota, Y. Formation of Surface Relief Grating Using a Novel Azobenzene-based Photochromic Amorphous Molecular Material. Adv. Mater. 2002, 14, 1157–1160, doi:10.1002/1521-4095(20020816)14:16<1157::AID-ADMA1157>3.0.CO;2-Z.
[21]
Nakano, H.; Tanino, T.; Shirota, Y. Surface Relief Grating Formation on a Single Crystal of 4-Dimethylaminoazobenzene. Appl. Phys. Lett. 2005, 87, doi:10.1063/1.2009065.
[22]
Nakano, H.; Tanino, T.; Takahashi, T.; Ando, H.; Shirota, Y. Relationship between Molecular Structure and Photoinduced Surface Relief Grating Formation Using Azobenzene-based Photochromic Amorphous Molecular Materials. J. Mater. Chem. 2008, 18, 242–246.
[23]
Nakano, H. Photoinduced Surface Relief Grating Formation on a Co-crystal of 4-[Bis(9,9-dimethylfluoren-2-yl)amino]azobenzene and Ethyl Acetate. Chem. Phys. Chem. 2008, 9, 2174–2176, doi:10.1002/cphc.200800419.
[24]
Nakano, H. Photoinduced Surface Relief Grating Formation on a (100) Surface of a Single Crystal of 4-(Dimethylamino)azobenzene. J. Phys. Chem. C 2008, 112, 16042–16045, doi:10.1021/jp804853q.
[25]
Nakano, H.; Takahashi, T.; Tanino, T.; Shirota, Y. Synthesis and photoinduced surface relief grating formation of novel photo-responsive amorphous molecular materials, 4-[bis(9,9-dimethylfluoren-2-yl)amino]-4'-cyanoazobenzene and 4-[bis(9,9-dimethylfluoren-2-yl)amino]-4'-nitroazobenzene. Dyes Pigm. 2009, 84, 102–107.
[26]
Nakano, H.; Seki, S.; Kageyama, H. Photoinduced vitrification near the surfaces of single crystals of azobenzene-based molecular materials with glass-forming ability. Phys. Chem. Chem. Phys. 2010, 12, 7772–7774, doi:10.1039/b926570h.
[27]
Nakano, H. Direction control of photomechanical bending of a photochromic molecular fiber. J. Mater. Chem. 2010, 20, 2071–2074, doi:10.1039/b924718a.
[28]
Nakano, H. Photoinduced Surface Relief Grating Formation for a Single Crystal of 4-Aminoazobenzene. Int. J. Mol. Sci. 2010, 11, 1311–1320, doi:10.3390/ijms11041311.
[29]
Nakano, H.; Suzuki, M. Photoinduced mass flow of photochromic molecular glasses. J. Mater. Chem. 2012, 22, 3702–3704, doi:10.1039/c2jm16517a.
[30]
Lee, K.M.; Wang, D.H.; Koener, H.; Vaia, R.A.; Tan, L.-S.; White, T.J. Enhancement of photogenerated mechanical force in azobenzene-functionalized polyimides. Angew. Chem. Int. Ed. 2012, 52, 4117–4121.
