R. Miyake et al., INVESTIGATION OF SHEATH FLOW CHAMBERS FOR FLOW CYTOMETERS - (MICRO MACHINED FLOW CHAMBER WITH LOW-PRESSURE LOSS), JSME international journal. Series B, fluids and thermal engineering, 40(1), 1997, pp. 106-113
A new type of sheath flow chamber with low pressure loss was developed
using micro-machining. The chamber was formed by laminating three 100
-mu m-thick, photo-etched, metal plates. The device uses sheath-flow g
eometry : particles in suspension, which enter the chamber via an axia
l specimen nozzle, are enveloped by a buffering sheath flow and transp
orted to a square capillary tube with cross-section of 300 mu m x 300
mu m. Finite element viscous-flow analysis is used to examine the flow
behavior in the quasi-two-dimensional passage configuration which pro
duces the fluid-dynamic focusing flow. Experimental measurement showed
a smooth constricted sheath flow, and pressure loss was reduced to on
e-tenth of that which occurs with conventional glass flow chambers.