Summary

Метод для изготовления наноструктур Disconnected серебро в 3D

Published: November 27, 2012
doi:

Summary

Фемтосекундного лазера прямого написания часто используется для создания трехмерных (3D) моделей в полимерах и стеклах. Тем не менее, структурирование металлов в 3D остается проблемой. Мы опишем способ изготовления серебряных наноструктур внедренные в полимерную матрицу помощью фемтосекундного лазера с центром в точке 800 нм.

Abstract

The standard nanofabrication toolkit includes techniques primarily aimed at creating 2D patterns in dielectric media. Creating metal patterns on a submicron scale requires a combination of nanofabrication tools and several material processing steps. For example, steps to create planar metal structures using ultraviolet photolithography and electron-beam lithography can include sample exposure, sample development, metal deposition, and metal liftoff. To create 3D metal structures, the sequence is repeated multiple times. The complexity and difficulty of stacking and aligning multiple layers limits practical implementations of 3D metal structuring using standard nanofabrication tools. Femtosecond-laser direct-writing has emerged as a pre-eminent technique for 3D nanofabrication.1,2 Femtosecond lasers are frequently used to create 3D patterns in polymers and glasses.3-7 However, 3D metal direct-writing remains a challenge. Here, we describe a method to fabricate silver nanostructures embedded inside a polymer matrix using a femtosecond laser centered at 800 nm. The method enables the fabrication of patterns not feasible using other techniques, such as 3D arrays of disconnected silver voxels.8 Disconnected 3D metal patterns are useful for metamaterials where unit cells are not in contact with each other,9 such as coupled metal dot10,11or coupled metal rod12,13 resonators. Potential applications include negative index metamaterials, invisibility cloaks, and perfect lenses.

In femtosecond-laser direct-writing, the laser wavelength is chosen such that photons are not linearly absorbed in the target medium. When the laser pulse duration is compressed to the femtosecond time scale and the radiation is tightly focused inside the target, the extremely high intensity induces nonlinear absorption. Multiple photons are absorbed simultaneously to cause electronic transitions that lead to material modification within the focused region. Using this approach, one can form structures in the bulk of a material rather than on its surface.

Most work on 3D direct metal writing has focused on creating self-supported metal structures.14-16 The method described here yields sub-micrometer silver structures that do not need to be self-supported because they are embedded inside a matrix. A doped polymer matrix is prepared using a mixture of silver nitrate (AgNO3), polyvinylpyrrolidone (PVP) and water (H2O). Samples are then patterned by irradiation with an 11-MHz femtosecond laser producing 50-fs pulses. During irradiation, photoreduction of silver ions is induced through nonlinear absorption, creating an aggregate of silver nanoparticles in the focal region. Using this approach we create silver patterns embedded in a doped PVP matrix. Adding 3D translation of the sample extends the patterning to three dimensions.

Protocol

1. Подготовка Металл-ионная полимерная пленка легированных Измерьте 8 мл воды в стакане. Добавить 206 мг PVP в воду. Смешать с использованием магнитной мешалки или вихревой смеситель, пока раствор не станет прозрачным. Добавить 210 мг AgNO 3 в растворе. Смешать с использов…

Representative Results

Акустооптического модулятора и фильтры нейтральной плотности (рис. 1) позволяют контролировать количество энергии, вложенной в образце. Использование экспозиции из 110 импульсов в воксела и 3 нДж на импульс, с этапом перевода на 100 мкм / сек, полученных структур серебра хорошо ви?…

Discussion

Ключом к процессу получения легированных диэлектрической матрице, что позволяет с высокой изготовление разрешение, но не ухудшает вскоре после приготовления. Простая смесь ПВП, AgNO 3 и H 2 O позволяет создавать высокое разрешение серебра наноструктур, внедренных в матрицу по?…

Disclosures

The authors have nothing to disclose.

Acknowledgements

Мы признаем, Paul Webster JL для 3D-рендеринга оптические данные с Amira. Фил Муньоса и Бенджамин Franta высказали свое мнение о рукописи всем протяжении ее развития. Исследования, описанные в этой статье была поддержана Управлением ВВС научные исследования в рамках грантов FA9550-09-1-0546 и FA9550-10-1-0402.

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Cite This Article
Vora, K., Kang, S., Mazur, E. A Method to Fabricate Disconnected Silver Nanostructures in 3D. J. Vis. Exp. (69), e4399, doi:10.3791/4399 (2012).

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