Guided assembly of nanowires and their integration in microfluidic devices
- PDF / 695,603 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 22 Downloads / 469 Views
Guided assembly of nanowires and their integration in microfluidic devices Josep Puigmarti-Luis1, Phillip Kuhn1, Benjamin Z. Cvetković1, Daniel Schaffhauser,1 Marta Rubio-Martínez2, Inhar Imaz2, Daniel Maspoch2 and Petra S. Dittrich1 1 Department of Chemistry and Applied Biosciences, ETH Zurich, Wolfgang-Pauli-Strasse 10, CH-8093 Zurich, Switzerland. 2 CIN2(ICN-CSIC), Catalan Institute of Nanotechnology, Esfera UAB, 08193 Bellaterra, Spain. ABSTRACT In this contribution, we present an effective strategy for assembling and integrating functional, in situ formed micro- and nanosized structures. Microfluidic platforms are employed to form anisotropic hybrid structures and coordination polymers at the interface of two precursor streams. Microstamps, embedded in the microfluidic device and actuated by pressure, provide a facile and reliable technology for structure trapping, localization and integration. INTRODUCTION During the last decade considerable attention has been focused on developing new techniques that enable localized and large-scale alignment of small building blocks such as micro- and nanowires into fully operative devices [1,2], e.g. for applications in the fields of photonics [3] and electronics [4]. Usually, integration and alignment of micro- and nanowires involve multiple steps, which are often complex, expensive and time-consuming processes. Therefore, a simple and universal method for integration of functional structures with high accuracy would strongly advance the development of devices based on nanostructures. Here, we present a novel and effective microfluidic strategy, in which synthesis, localization, and direct integration of functional wires are accomplished in situ, and at desired locations inside multilayer microfluidic platforms. Two types of materials are utilized: Hybrid wires made of gold and tetrathiafulvalen (Au-TTF)[5] and nanoscaled coordination polymers (here: copper-aspartic acid) [6,7].
EXPERIMENTAL DETAILS Fabrication of microfluidic platforms: All chips are made of poly(dimethylsiloxane) (PDMS), and are prepared by means of standard soft lithography techniques as described elsewhere [8-10]. Two generations of microfluidic platforms are used in our experiments consisting of two layers (Fig. 1). The bottom layer (fluid layer) comprises four input channels (50 µm wide), merging into a wide channel (200 µm wide). The height is 50 µm. The second layer (the control layer) comprises the microstamp designs, here with rectangular and donut-like shapes. The difference between the first-generation and the second-generation devices is the presence of a thin and flexible PDMS membrane. Figure 1(a) and 1(b) show schematic side views of the first, called hereafter “freestanding membrane-based chip”, and the second-generation chip, respectively. Synthesis and trapping of Cu(II)-Asp nanowires. For the experiments described here, we employ the two-layer chip design. In a typical synthesis of Cu(II)-Asp nanowires, Cu(NO3)2·3H2O (1.5 mM) in water, and an aqueous solution of L- aspartic acid (1.0
Data Loading...
