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Watanabe, Toshiyuki; Akiyama, Masayasu; Totani, Kiichiro; Kuebler, Stephen M.; Stellacci, Francesco; Wenseleers, Wim; Braun, Kevin L.; Marder, Seth R.; Perry, Joseph W.

doi:10.1002/1616-3028(20020916)12:9<611::aid-adfm611>3.0.co;2-3

Cited by 140 publications

(62 citation statements)

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“…MPP was first developed by Strickler and Webb, [62] and has now been used to create a range of high-resolution 3D free-form structures, including microchannels, [63][64][65] cantilevers, [66][67][68] microgears, [69,70] sub-micrometer oscillators, [71] hydrophobic atomic force microscopy tips, [72] and PhCs. [59,67,[73][74][75][76][77][78][79][80][81] Briefly, MPP utilizes the nonlinear nature of the multiphoton excitation process to only excite dye molecules in a very small volume around the focal point, with dimensions on the order of the resolution limit.…”

Section: Direct Writingmentioning

confidence: 43%

Introducing Defects in 3D Photonic Crystals: State of the Art

2006

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Public Reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comment regarding this burden estimates or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188,) Washington, DC 20503. AGENCY USE ONLY ( Leave Blank)2. REPORT DATE Advanced Materials, 18, 2665-2678 (2006). 3D photonic crystals (PhCs) and photonic bandgap (PBG) materials have attracted considerable scientific and technological interest. In order to provide functionality to PhCs, the introduction of controlled defects is necessary; the importance of defects in PhCs is comparable to that of dopants in semiconductors. Over the past few years, significant advances have been achieved through a diverse set of fabrication techniques. While for some routes to 3D PhCs, such as conventional lithography, the incorporation of defects is relatively straightforward; other methods, for example, selfassembly of colloidal crystals (CCs) or holography, require new external methods for defect incorporation. In this review, we will cover the state of the art in the design and fabrication of defects within 3D PhCs. The figure displays a fluorescence laser scanning confocal microscopy image of a y-splitter defect formed through two-photon polymerization within a CC. SUBJECT TERMS 15. NUMBER OF PAGES 1416. PRICE CODE SECURITY CLASSIFICATION OR REPORT UNCLASSIFIED SECURITY CLASSIFICATION ON THIS PAGE UNCLASSIFIED SECURITY CLASSIFICATION OF ABSTRACT UNCLASSIFIED LIMITATION OF ABSTRACT UL IntroductionPhotonic crystals (PhCs) are materials that possess spatial periodicity in their dielectric constant on the order of the wavelength (k) of light. These materials can strongly modulate light [1] and, with sufficient dielectric contrast and an appropriate geometry, may exhibit a photonic bandgap (PBG). This concept was first proposed in 1975 by Bykov [2] but remained relatively unknown until the seminal work of Yablonovitch [3] and John. [4] In a rough analogy to semiconductors, which possess an electronic bandgap, a PBG material prohibits the existence of photons with energies in the PBG. PhCs are naturally classified by the dimensionality of their periodicity, and in order to rigorously prevent the propagation of PBG frequencies in all directions, a 3D PhC with an omnidirectional, or complete PBG (cPBG) is required. cPBG materials have been fabricated and well characterized for operation at microwave and radio frequencies, however, operation in the visible and IR requires the characteristic length scales of these structures to be scaled down by several orders of magnitude...

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Section: Direct Writingmentioning

confidence: 43%

Introducing Defects in 3D Photonic Crystals: State of the Art

2006

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“…Researchers have taken various approaches to fabricating biomimetic actuators, among which are biomorph actuators made using Micro Electromechanical Systems (MEMS) technology, [9] magnetically actuated poly(dimethylsiloxane) (PDMS) structures, [10] and artificial cilia or actuators made from responsive gel. [11,12] However, most fabricated actuators, such as MEMS or magneticallyactuated PDMS posts, must be driven by an external force or field and are not responsive to chemical stimuli. Actuating structures that have been made from responsive hydrogel are Submitted to 2 either low aspect ratio and their motion is not patternable, [11] or the movement is irreversible.…”

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confidence: 44%

“…Actuating structures that have been made from responsive hydrogel are Submitted to 2 either low aspect ratio and their motion is not patternable, [11] or the movement is irreversible. [12] Microscale actuation systems which exhibit reversible chemo-mechanical response and control of actuation direction or pattern have proven difficult to achieve.Inspired by biological actuators, which can be broadly interpreted as composites consisting of an active "muscle" component coupled with a passive "bone" structure, we recently developed a hybrid actuation system in which a crosslinked acrylamide-based hydrogel, acting as an analog to muscle, drives the movement of embedded silicon [13,14] or polymer [15] microposts, serving as analogs to skeletal elements. Actuation was achieved by the swelling and contraction of the humidity-responsive gel upon hydration/drying.…”

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Bio‐inspired Design of Submerged Hydrogel‐Actuated Polymer Microstructures Operating in Response to pH

2011

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Responsive and reversibly actuating surfaces have attracted significant attention recently due to their promising applications as dynamic materials [1] that may enable microfluidic mixing, [2] particle propulsion and fluid transport, [3] capture and release systems, [4] and antifouling. [5] Analogs in nature serve as inspiration for the design of such advanced adaptive materials systems⎯microorganisms use flagella for propulsion, [6] cilia line the human respiratory tract to sweep mucus from the lungs and prevent bacterial accumulation, [7] and echinoderms use pedicellariae for body cleaning and food capture. [8] Significant characteristics of these biological systems include functionality in a fluidic environment, controllable actuation direction or pattern, and the ability to translate chemical signals or stimulus into mechanical motion. Researchers have taken various approaches to fabricating biomimetic actuators, among which are biomorph actuators made using Micro Electromechanical Systems (MEMS) technology, [9] magnetically actuated poly(dimethylsiloxane) (PDMS) structures, [10] and artificial cilia or actuators made from responsive gel. [11,12] However, most fabricated actuators, such as MEMS or magneticallyactuated PDMS posts, must be driven by an external force or field and are not responsive to chemical stimuli. Actuating structures that have been made from responsive hydrogel are Submitted to 2 either low aspect ratio and their motion is not patternable, [11] or the movement is irreversible. [12] Microscale actuation systems which exhibit reversible chemo-mechanical response and control of actuation direction or pattern have proven difficult to achieve.Inspired by biological actuators, which can be broadly interpreted as composites consisting of an active "muscle" component coupled with a passive "bone" structure, we recently developed a hybrid actuation system in which a crosslinked acrylamide-based hydrogel, acting as an analog to muscle, drives the movement of embedded silicon [13,14] or polymer [15] microposts, serving as analogs to skeletal elements. Actuation was achieved by the swelling and contraction of the humidity-responsive gel upon hydration/drying. Actuation direction was controlled by modulating the hydrogel thickness; since thicker hydrogel exhibits a greater absolute change in volume than thin hydrogel, the forces exerted on the structures⎯and thus their actuation direction⎯can be patterned.However, a humidity responsive system will not function in the fluidic environment required for many applications such as propulsion, cargo transport, or microfluidics, and it is difficult to pattern uni-directional actuation of posts over large areas due to their lack of preferred bending direction. To enable the actuators to function in various environments, it is possible to alter the chemistry of the hydrogel muscle to make it shrink or swell while submerged in response to a range of stimuli including light, [16] temperature, [17] biomolecules (e.g. glucose), [18] or pH. [19] To gain additional ...

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“…We selected readily 35 available acrylic monomer Bisphenol A ethoxylate diacrylate (BPA-EDA) with three different photo- deposition [6], LIGA (X-ray-lithography, electro-forming and mold-56 ing) [7], focused-ion-beam [8,9] and laser holographic lithography 57 [10]. While these techniques allows for fabrication of 3D struc- Direct laser writing (DLW) based two-photon polymerization 63 [11], being a true 3D maskless lithography, with reproducible even 64 sub 100 nm resolution [12], has then recently gained increasing 65 attention in areas such as optics, biology and electronics [13][14][15][16][17][18][19][20]. the cost for the Ti:sapphire system is relatively high, so there's an 87 increasing request for materials that could adapt to the emerging 88 technology of the less expensive femtosecond fiber lasers [23,24] 89 that have the constraint of working at a fixed NIR wavelength (usu-90 ally 780 nm).…”

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confidence: 44%