title: A self-priming, roller-free, miniature, peristaltic pump operable with a single, reciprocating actuator.
abstract: We present a design for a miniature self-priming peristaltic pump actuated with a single linear actuator, and which can be manufactured using conventional materials and methods. The pump is tolerant of bubbles and particles and can pump liquids, foams, and gases. We explore designs actuated by a motor (in depth) and a shape memory alloy (briefly); and briefly present a manually actuated version. The pump consists of a Delrin acetal plastic body with two integrated valves, a flexible silicone tube, and an actuator. Pumping is achieved as the forward motion of the actuator first closes the upstream valve, and then compresses a section of the tube. The increased internal pressure opens a downstream burst valve to expel the fluid. Reduced pressure in the pump tube allows the downstream valve to close, and removal of actuator force allows the upstream valve and pump tube to open, refilling the pump. The motor actuated design offers a linear dependence of flow rate on voltage in the range of 1.75-3 V. Flow rate decreases from 780 μl/min with increasing back pressure up to the maximum back pressure of 48 kPa. At 3 V and minimum back pressure, the pump consumes 90 mW. The shape memory alloy actuated design offers a 5-fold size and 4-fold weight reduction over the motor design, higher maximum back pressure, and substantial insensitivity of flow rate to back pressure at the cost of lower power efficiency and flow rate. The manually actuated version is simpler and appropriate for applications unconstrained by actuation distance.
authors.affiliation: Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA.
authors.forename: Viktor
authors.initials: V
authors.lastname: Shkolnikov
authors.affiliation: Department of Neuroscience, Stanford University, Stanford, CA 94305, USA.
authors.forename: John
authors.initials: J
authors.lastname: Ramunas
authors.affiliation: Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA.
authors.forename: Juan G
authors.initials: JG
authors.lastname: Santiago
keywords: Biocompatible pump; Micropump; Miniature pump; Peristaltic pump; Plastic pump; Self-priming