Fabrication of Self-sealed Vertical Polymeric Nano-junctions for Microfluidic Devices


  • High-throughput ion/protein pre-concentration
  • Nanofluidic pumps for high throughput sample preparation

Problem Addressed

This technology provides a method for creating nanostructures embedded in PDMS-based microchips.


Nanofluidic systems have been widely studied in recent years, enabled by advances in micro/nanofabrication technologies. Polymeric materials, including PDMS and PMMA, have become widely used for disposable microfluidics because of straight-forward fabrication processes and low cost. Current methods for producing nanostructures within PDMS suffer from reproducibility issues due to the shifting chemical nature of PDMS surfaces. Moreover, because existing techniques can only create nanostructures at the interface of PDMS and cover materials, only low aspect ratio nanostructures can be fabricated. These junctions typically have nanometer scale depth and micrometer scale width, which may lead to poor coupling between nano-junctions and microchannels. The current technology presents a device and novel fabrication method for polymeric nanostructures integrated within PDMS microchips. The method bypasses complicated microfabrication techniques and complex chemical treatments on PDMS-polymer surfaces, by taking advantage of the flexibility of PDMS to provide a device with robust, reliable seals between PDMS and any heterogeneous polymer materials. This method addresses the problems in standard PDMS microchannels of system integration and diverse chemical functionality.


  • Quick and easy nano-junction fabrication; no clean room necessary
  • Fabrication technique does not require considerable training, thereby expediting the process
  • Nano-junctions can be fabricated to microchannel height, allowing for strong concentration polarization for fast ion/protein pre-concentration
  • Allows for pressure-driven pre-concentration
  • Nano-junctions are tightly sealed ensuring minimal leakage
  • Any polymeric material with nano-sized pores can be used because of self-sealing nature in material
  • Nonspecific molecule absorption minimized because nano-junction contact with the glass substrate is minimal
  • Flow rate in microchannel is superior to any current electroosmotic pumping