Low-cost, monolithically 3D-printed, miniature high-flow rate liquid pump

Abstract

We report the design, fabrication, and characterization of the first monolithically 3D-printed, high-flow rate miniature liquid pumps in the literature. Our low-cost, leak-tight, miniature devices are microfabricated using 150 to 300 μm layers in pure Nylon 12 via fused filament fabrication with a multi-step printing process that monolithically creates all key features with <13 μm in-plane misalignment. Each pump has a rigid frame, a 21 mm-diameter, 150 μm-thick membrane connected at its center to a piston with an embedded magnet, a chamber, passive ball valves, and two barbed fluidic connectors. Pump fabrication under 2 hours and costs less than $4.65 (about $0.65 in printable feedstock). Finite element analysis of the actuator predicts a maximum stress of 18.7 MPa @ 2 mm deflection, i.e., about the fatigue limit of Nylon 12 for infinite life (i.e., 19 MPa). A maximum water flow rate of 1.37 ml/min at 15.1 Hz actuation frequency is calculated -comparable to reported values of miniature liquid pumps with up to two orders of magnitude higher actuation frequency.