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In this paper, we reported an effective microfluidic-based method for fast continuous synthesis of monodisperse PEG/SiO2 hybrid microspheres. The T-junction microfluidic chip equipped with rounded channels and the online photopolymerization system were applied for the microspheres microfabrication. The size of the microspheres was well controlled by the rounded channels and flow rate ratios of immiscrible fluids. We can obtain porous PEG microspheres when the hybrid microspheres were corroded by hydrofluoric acid. What's more, the interpenetrating polymer network structures of SiO2 microspheres were obtained after the hybrid microspheres treated via a calcination process.

Microfluidic chip electrophoresis (MCE) is a powerful separation tool for biomacromolecule analysis. However, adsorption of biomacromolecules, particularly proteins onto microfluidic channels severely degrades the separation performance of MCE. In this paper, an anti-protein-fouling MCE was fabricated using a novel sandwich photolithography of poly(ethylene glycol) (PEG) prepolymers. Photopatterned microchannel with a minimum resolution of 10 μm was achieved. After equipped with a conventional online electrochemical detector, the device enabled baseline separation of bovine serum albumin, lysozyme (Lys), and cytochrome c (Cyt-c) in 53 s under a voltage of 200 V. Compared with a traditional polydimethylsiloxane MCE made by soft lithography, the PEG MCE made by the sandwich photolithography not only eliminated the need of a master mold and the additional modification process of the microchannel but also showed excellent anti-protein-fouling properties for protein separation.

In this paper, we present microfabrication of a novel photopatternable conductive PDMS material with silver powder as conductive filler and benzophenone as photosensitive component, employing standard photolithography approach. An array of miniaturized capacitive pressure sensors is micromachined onto flexible polymeric transparency using this approach. Highest conductivity of ∼104 S·m−1 and minimal feature resolution of 60 µm have been successfully achieved. In addition, a thermal compression step can mold the microfabricated device into a desired shape (e.g., contact lens). The unique combination of physical properties from both silver filler and PDMS matrix along with photopatternability makes the conductive PDMS composite an excellent material for biological and clinical sensing applications.

Conductive photodefinable polydimethylsiloxane (PDMS) composites that provide both high electrical conductivity and photopatternability have been developed. The photosensitive composite materials, which consist of a photosensitive component, a conductive filler, and a PDMS pre-polymer, can be used as a negative photoresist or a positive photoresist with an additional curing agent. A standard photolithographic approach has been used to fabricate conductive elastomeric microstructures. Feature sizes of 60 µm in the positive photoresist and 10 µm in the negative photoresist have been successfully achieved. Moreover, as the conductive filler, silver powders significantly improve the electrical conductivity of the PDMS polymer, but also provide enhanced mechanical and thermal properties as well as interesting biological properties. The combined electrical, mechanical, thermal, and biological properties along with photopatternability make the PDMS-Ag composite an excellent processable and structural material for various microfabrication applications.

An effective microfluidic method to fabricate monodisperse polyethylene glycol (PEG) hydrogel composite microspheres with tunable dimensions and properties is reported in this paper. A T-junction microfluidic chip equipped with rounded channels and online photopolymerization system is applied for the microsphere microfabrication. The shape and size of the microspheres are well controlled by the rounded channels and PEG prepolymer/silicon oil flow rate ratios. The obtained PEG/aspirin composite microspheres exhibit a sustained release of aspirin for a wide time range; the obtained PEG/Fe3O4?nanocomposite microspheres exhibit excellent magnetic properties; and the obtained binary PEG/dye composite microspheres show the ability to synchronously load two functional components in the same peanut-shaped or Janus hydrogel particles.