This article demonstrates, through finite element analysis, the possibility to manufacture sub-30 nm polymeric channels using electrostatic induced lithography. Channels with a width of 25 nm, a depth of 50 nm and an inter-channel wall of 28 nm can be obtained by this patterning process. The influence of operational parameters such as the filling factor, the aspect ratio of the master electrode, the applied voltage and the gap between the two electrodes and initial film thickness has been studied in detail to define the fabrication limits of this process in the case of periodic nanostructures. Conclusions for such nanostructures can be generalised to other shapes manufactured from polymers.

Hollow microstructures serve many useful applications in the fields of microsystems, chemistry, photonics, biology and others. Current fabrication methods of artificial hollow microstructures require multiple fabrication steps and expensive manufacturing tools. The paper reports a unique one-step fabrication process for the growth of hollow polymeric microstructures based on electric fieldassisted capillary action. This method demonstrates the manufacturing of self-encapsulated microstructures such as hollow microchannels and microcapsules of around 100-lm height from an initial polymer thickness of 22 lm. Microstructure caps of several microns thickness have been shown to keep their shape under bending or delamination from the substrate. The inner surface of hollow microstructures is shown to be smooth, which is difficult to achieve with current methods. More complicated structures, such as a microcapsule array connected with hollow microchannels, have also been manufactured with this method. Numerical simulation of the resist growth process using COMSOL Multiphysics finite element analysis software has resulted in good agreement between simulated and experimental results on the overall shape of the resulting structures. These results are very positive and demonstrate the speed, versatility and cost-effectiveness of the method.

This article demonstrates the manufacturing of microstructures in a thick polymer using electrostatic-induced lithography. Unlike previous work reported elsewhere, it focuses on the fabrication of structures from meso-to micro-scale. The electrostatic-induced lithography technique is proven to work with not only dc voltage but also ac voltage. Microstructures including microchannels, sinusoidal surface profile microstructures, waveguide core, microlens array and binary Fresnel zone plate have been successfully fabricated. The aspect ratio obtained for some samples is up to 4.5:1. The whole fabrication process is fast, cost-effective in terms of the simple experimental setup and no photosensitive material is needed. This process is expected to find applications in microfluidics, photonics or micro-opto-electro-mechanical systems.

No abstract