Micro-sorting device by a micro-channel with multiple-size pores

We present the fabrication of micro-sorting device with multiple-size pores micro-channel. The porous micro-channel has 1, 3, and 5 μm diameter. It was fabricated by direct laser writing. It was designed to connect with micro-channels which were fabricated by UV lithography process. The multiple-size pores micro-channel was made of IP-L as photoresist. The PDMS micro-channel has also been fabricated and assembled on the glass with the IP-L porous micro-channel. A fluid flow test was conducted to the multiple-size pores micro-channel to test the leakage of fluid through the pores on the IP-L material. A micro bead was observed to trap inside the pore. It can be concluded that the pore has less than 100nm diameter. The micro bead is captured due to the pressure gradient between the inside and outside of the multiple-size pores micro-channel. This device has the potential to be used as cell sorter in DNA purification and bacteria filtering.