| This thesis describes three new techniques that were developed for micro-fabrication. The first of these techniques—microlens array lithography—is applicable to the fabrication of repetitive planar structures. This method used arrays of microlenses embedded in a transparent, elastomeric polymer to project a cm-scale, illuminated pattern into many micron-scale images in photoresist, and simultaneously to reduce the pattern in size by a factor of 1000. It was able to expose areas of several cm2 in a single exposure. By changing the orientation of the mask with respect to the array, a single mask and array could generate a range of patterns. The second technique provides new routes to 3D systems of microchannels and microstructures with arbitrary topology. These systems were formed by decomposing them into substructures that could be fabricated separately with conventional planar lithography and soft lithography, and joining the substructures. The third technique uses self-assembly based on capillarity to form 2D and 3D ordered lattices of mm-sized objects. PDMS plates floating at the perfluorodecalin/water interface assembled into 2D arrays through interactions between the menisci on the faces of the plates. A more complicated technique used hierarchical self-assembly to fabricate extended structures of ∼mm-sized spherical beads. All of these techniques emphasized simplicity and convenience, and were designed to make microfabrication more accessible to chemists, physicists, and materials scientists. |
