3D designing of resist membrane pores via direct electron beam lithography

Formation of fluidic channels with well-defined size and shape is of critical importance for reliable resistive pulse sensing of individual objects in electrolyte solution. Here we report on a method to fabricate a pore of 3Dcontrolled structure. We directly sculpted a hole in a polymer resist membrane of various thickness up to 6 mu m by electron beam lithography. This procedure allowed to create diverse range of thickness-to-diameter aspect ratio channels of controllable shapes from concave to convex cone profiles via the varying proximity effects under different electron dose conditions. The lithographically-defined pores were utilized to detect nanoparticles by cross-membrane ionic current that revealed optimal membrane thickness for gaining larger resistive pulse signal intensities. The present technique provides a way to design single-particle sensors for cell sorting and viral screening.

Automated summary

A method was reported to fabricate well-defined fluidic channels for reliable resistive pulse sensing of individual objects in electrolyte solution. The technique involves direct sculpting of holes in polymer resist membrane using electron beam lithography, allowing creation of channels with controlled shapes and sizes. These lithographically-defined pores can be utilized in designing single-particle sensors for cell sorting and viral screening.