Finger-operated pumping platform for microfluidic preparation of nanoparticles

Microfluidic preparation of nanoparticles (NPs) offers many advantages over traditional bench-top preparation techniques, including better control over particle size and higher uniformity. Although many studies have reported the use of low-cost microfluidic chips for nanoparticle synthesis, the technology is still expensive due to the high cost of the pumps needed to generate the required flows inside microchannels. Here, we present a low-cost finger-operated constant-pressure pumping platform capable of generating pressures as high as 120 kPa using finger-operated pumping caps that can be attached to any pop bottle. The platform costs around $208 and enables the generation of flow rate ratios (FRR) of up to 47:1 for the continuous flow synthesis of NPs. The pump has a resolution of 500 Pa per stroke and exhibits stable pressures for up to a few hours. To show the functionality of the proposed pump, we used it to prepare pegylated liposomes and poly lactic-co-glycolic acid (PLGA) nanoparticles with sizes ranging from 47 nm to 250 nm with an average polydispersity of 20% using commercially available micromixer chips and in-house made hydrodynamic flow focusing devices. We believe this platform will render microfluidic preparation of NPs accessible to any laboratory with minimal capabilities.