Maskless fabrication of small-scale structures through controlling phase interactions

We present a technique to create three-dimensional (3-D) microstructures using optical phase interactions with photocuring chemistry. We formulated a photocurable poly(dimethylsiloxane) (photoPDMS) consisting of a (methacryloxypropyl)methylsiloxane-dimethylsiloxane copolymer and a photoinitiator 2,2-dimethoxy-2-phenyl-acetophenone. By activating the photoPDMS, in combination with controlling the phase interactions between photoPDMS and an immiscible liquid, in situ fabrication of 3-D polymeric microstructures was achieved. This method has potential applications in a variety of fields including building 3-D complex structures for small-scale tissue engineered scaffolds and using these fabricated optical polymer lenses in lab-on-chip technology.