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1.
ACS Nano ; 13(4): 4041-4048, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-30677287

RESUMO

Strategies that can make general materials smart are highly desired for developing artificial shape-morphing systems and devices. However, at present, it still lacks universal technologies that enable designable prototyping of deformable 3D micro-nanostructures. Inspired by natural automation systems, for instance, tendrils, leaves, and flowers deform dynamically under external stimuli by varying internal turgor, we report a dual-3D femtosecond laser processing strategy for fabricating smart and deformable 3D microactuators based on general photopolymers. By programming the size and distributions of voxels at the nanoscale, both the 3D profile and the 3D internetwork of a general photopolymer could be tailored in a controlled manner; thus, 3D microstructures encoded with precisely tailored networks could perform predictable deformations under certain stimuli. Using this dual-3D fabrication approach, energetic 3D microactuators, including a smart microflower, a responsive microvale, and an eight-finger microclaw, that permit controllable manipulation have been successfully developed.

2.
Lab Chip ; 15(6): 1515-23, 2015 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-25622687

RESUMO

Optimal design and fabrication of novel devices for high-performance optofluidic applications is a key issue for the development of advanced lab-on-a-chip systems. Parallel cell counting with a high success rate and simple mode of operation is a challenging goal. Current cell-counting methods, using optical waveguides or flow cytometry, typically require a precise coupling of the probe light and involve complex operations. In the present paper, a novel multifunctional cell counting microdevice is designed. It uses a center-pass optofluidic microlens array (MLA) consisting of seven microlenses and an M-shaped confining wall with 9 µm-diameter apertures. The device can be fabricated in a three-dimensional microchannel by ship-in-a-bottle femtosecond laser integration based on two-photon polymerization with optimized experimental parameters. Each microlens produces approximately the same intensity at the focal positions (within ±5%) under white-light illumination, while the confining wall restricts 6∼8 µm-width cells to passing through the edges of two adjacent microlenses because the aperture opens toward their centers. The device demonstrates coupling-free parallel cell counting with a 100% success rate by monitoring the optical intensity variations at each spot. As a result, this method features both easy operation and high performance. Furthermore, the confining wall can filter deformed cells having 15 µm width.


Assuntos
Contagem de Células/instrumentação , Lasers , Lentes , Técnicas Analíticas Microfluídicas/instrumentação , Integração de Sistemas , Desenho de Equipamento , Vidro
3.
Opt Lett ; 38(19): 3739-42, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-24081040

RESUMO

An elliptical monolithic bifocal zone plate as a collimating lens, whose two focal lengths in the orthogonal directions match the different beam waist positions of the fast and slow axes' light from edge-emitting laser diodes, is proposed and experimentally demonstrated by employing femtosecond laser direct writing technology. The high-quality eight-level zone plate exhibits a diffraction efficiency of 92.9%, which is much higher than those ever reported. Shaped by the elliptical lens, the laser diodes' divergence angles are simultaneously reduced from 65° (1134 mrad, fast axis) and 24° (418 mrad, slow axis) to 7.7 and 136.5 mrad, respectively.

4.
Phys Chem Chem Phys ; 15(24): 9590-3, 2013 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-23666225

RESUMO

We report the fabrication of three-dimensional periodic metal nickel nanostructures achieved by the combination of femtosecond laser-induced two-photon polymerization and electroless plating technology. We can control the deposition speed of 10 nm per second by adjusting the reaction time. The thermal stability is good under 500 °C for the three-dimensional graphite-lattice polymer structure with 200 nm nickel film. Optical reflectivity and thermal emission measurements under 550 °C showed that the fabricated metallic structure was thermally excited and emitted light at λ = 4.50, 4.95 µm. The emission peak wavelengths agree with the absorption peaks. These data demonstrate that creating metallic photonic crystals by incorporation of metals to laser-fabricated templates is a simple and cost-efficient method. The emitters can work at such low temperatures, which is more important for realistic operation in applications.

5.
Lab Chip ; 11(19): 3347-51, 2011 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-21863148

RESUMO

We report here a facile approach for flexible integration of high efficiency surface enhanced Raman scattering (SERS) monitors in a continuous microfluidic channel. In our work, femtosecond laser direct writing was adopted for highly localizable and controllable fabrication of the SERS monitor through a multi-photon absorption (MPA) induced photoreduction of silver salt solution. The silver substrate could be shaped into designed patterns, and could be precisely located at the desired position of the microchannel bed, giving the feasibility for real-time detection during reactions. SEM and TEM images show that the silver substrates were composed of crystallized silver nanoplates with an average thickness of 50 nm. AFM results reveal that the substrates were about 600 nm in height and the surface was very rough. As representative tests for SERS detection, p-aminothiophenol (p-ATP) and flavin adenine dinucleotide (FAD) were chosen as probing molecules for microfluidic analysis at visible light (514.5 nm) excitation, exhibiting an enhancement factor of ~10(8). In addition, the combination of the SERS substrate with the microfluidic channel allows detection of inactive analytes through in situ microfluidic reactions.

8.
Langmuir ; 26(14): 12012-6, 2010 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-20499864

RESUMO

In this paper, one simple method to control two-direction anisotropic wetting by regular micropearl arrays was demonstrated. Various micropearl arrays with large area were rapidly fabricated by a kind of improved laser interference lithography. Specially, we found that the parallel contact angle (CA) theta(2) decreased from 93 degrees to 67 degrees as the intensity ratio of four laser beams increased from 2:1 to 30:1, while the perpendicular CA theta(1) determined by the thickness of the resin remained constant. This was interpreted as the decrease of height variations Delta h from 1100 to 200 nm along the parallel direction caused by the increase of the intensity ratio. According to this rule, both theta(1) and theta(2) could be simultaneously controlled by adjusting the height variation Delta h and the resin thickness. Moreover, by combining appropriate design and low surface energy modification, a natural anisotropic rice leaf exhibiting CAs of 146 degrees +/- 2 degrees/153 degrees +/- 3 degrees could be mimicked by our anisotropic biosurface with the CAs 145 degrees +/- 1 degrees/150 degrees +/- 2 degrees. We believe that these controlled anisotropic biosurfaces will be helpful for designing smart, fluid-controllable interfaces that may be applied in novel microfluidic devices, evaporation-driven micro/nanostructures, and liquid microdroplet directional transfer.


Assuntos
Biomimética/instrumentação , Microesferas , Anisotropia , Biomimética/economia , Lasers , Propriedades de Superfície , Fatores de Tempo , Molhabilidade
9.
Lab Chip ; 10(15): 1993-6, 2010 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-20508876

RESUMO

This paper demonstrates the embellishment of existing microfluidic devices with integrated three dimensional (3D) micronanostructures via femtosecond laser micronanofabrication, which, for the first time, proves two-photon photopolymerization (TPP) to be a powerful technology for chip functionalization. As representative examples, microsieves with various pore shape and adjustable pore size were successfully fabricated inside a conventional glass-based microfluidic channel prepared by wet etching for microparticle separation. Moreover, a fish scale like microfilter was also fabricated and appointed as a one-way valve, which showed excellent performance as we expected. These results indicate that such embellishment of microfluidic devices is simple, low cost, flexible and easy to access. We believe that, combined with TPP, the application of lab-on-chip devices would be further extended.


Assuntos
Dispositivos Lab-On-A-Chip , Lasers , Técnicas Analíticas Microfluídicas/métodos , Processos Fotoquímicos , Técnicas Analíticas Microfluídicas/instrumentação
10.
Nan Fang Yi Ke Da Xue Xue Bao ; 29(11): 2237-40, 2009 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-19923077

RESUMO

OBJECTIVE: To investigate the relationship between positive expression of Her2 and abnormal expressions of beta-catenin and E-cadherin and its implications. METHODS: Immunohistochemistry was used to detect the expressions of Her2, beta-catenin and E-cadherin in 147 samples of human breast carcinoma. The expressions of beta-catenin and E-cadherin were also detected in 19 tissues adjacent to the carcinoma and 17 benign breast lesions as controls. RESULTS: In breast carcinoma, positive Her2 expression was associated with lymph node metastasis, advanced clinical stage and negative expression of ER and PR (P<0.05). Abnormal beta-catenin expression was associated with positive lymph node status and high histological grade (P<0.01). Abnormality of E-cadherin expression was related to lymph node metastasis and advanced clinical stage (P<0.05). Abnormal beta-catenin expression was directly correlated with abnormal E-cadherin expression (P<0.01). Her2 positivity showed a direct correlation to abnormal beta-catenin expression (P<0.01), and they cooperated in promoting axillary lymph node metastasis in human breast carcinoma (P<0.01). CONCLUSION: A direct correlation between positive Her2 expression and abnormal beta-catenin expression exists in human breast carcinoma, and positive Her2 expression may have functional interactions with abnormal activation of Wnt/beta-catenin signaling pathway.


Assuntos
Neoplasias da Mama/metabolismo , Caderinas/metabolismo , Carcinoma Ductal de Mama/metabolismo , Receptor ErbB-2/metabolismo , beta Catenina/metabolismo , Adulto , Idoso , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , beta Catenina/genética
11.
Lab Chip ; 9(16): 2391-4, 2009 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-19636471

RESUMO

Microfluidic researches are now resorting to advanced micro-nanoprocessing technologies for production of more functional "lab-on-a-chip" systems. However, two-photon polymerization (TPP), a powerful designable micro-nanofabrication approach, has not been put to use on the exciting field, largely due to the difficulties in forming buried channels. Here, we solve the problem by TPP prototyping of nanoshells, for which the usage of the negative tone resin SU-8 is found critical. The fabrication efficiency improved by orders of magnitude, together with the prospect of integration of movable micro-mechanical and optical components into the chip would make TPP a promising enabling tool for the micro-analytical systems. Finally, a 25 microm length functional microvalve in a microfluidic channel was rapidly realized and its "ON" and "OFF" states were tested.


Assuntos
Lasers , Técnicas Analíticas Microfluídicas/métodos , Nanotecnologia , Técnicas Analíticas Microfluídicas/instrumentação , Fótons , Polímeros/química , Solventes/química , Fatores de Tempo , Raios Ultravioleta
12.
Opt Lett ; 34(5): 581-3, 2009 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-19252558

RESUMO

We report remote manipulation of micronanomachines containing magnetic nanoparticles. Surface-modified Fe(3)O(4) nanocrystals were synthesized as doping agents of the photopolymerizable resin, which was pinpoint written by femtosecond laser-induced two-photon photopolymerization to create microsprings. Owing to the nature of superparamagnetism of Fe(3)O(4) nanoparticles, force exerted to the microsprings relies sensitively on the field gradient of the external ferromagnet, and various motions like elongation, bending, and swing are achieved in a well-controllable remote manner. As a noncontact, sensitive, easy, and environmentally friendly approach, the magnetic driving of micronanomachines may play an important role for nano and biological applications.

13.
Opt Lett ; 33(24): 2913-5, 2008 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-19079490

RESUMO

Three kinds of high efficiency phase-type fractal zone plates were rapidly (in tens of minutes) fabricated by femtosecond laser two-photon photopolymerization. Their theoretical maximal diffractive efficiencies of 24.5%, 12.52%, and 18.76% were predicted both by numerical simulation and analytical deduction and were verified by the measured values of 20.5%, 9.1%, and 13%, respectively. The characteristic of multifoci and the improved imaging ability for phase-type fractal lens was also demonstrated. Moreover, to further enhance the diffractive efficiency, a four-level fractal phase lens, whose diffraction efficiency reached as high as 37.6%, was proposed and realized.

14.
Opt Lett ; 33(21): 2559-61, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18978920

RESUMO

Dammann gratings, as beam splitters and coherent signal generators, were produced in a short fabricating cycle by femtosecond laser fabrication via two-photon photopolymerization. These holograms that each generated 2x2, 3x3, 4x4, 5x5, and 6x6 spot sources in the fan-out demonstrated diffraction efficiency of 36%, 25%, 29%, 52%, and 49%, respectively, comparable with the theoretical values. This work shows the promising prospect of femtosecond laser fabrication in compatibly manufacturing various micro-optical devices including Dammann gratings and their integrated systems.

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