A device for sorting soft capsules in a microchannel flow

The sorting of deforming capsules of varying stiffnesses is a challenging problem that finds applications in areas such as the pharmaceutical and food industries. Recent studies have shown that various flow configurations can be used to segregate the capsules. A lack of inertia in the microchannels makes the design of such devices extremely challenging. In this context, we propose a sorting device, which consists of capsules going through a tapered slit section. Using numerical simulations, we show that the proposed device is able to achieve significant levels of sorting with a compact setup. The design parameters can be conveniently adjusted, thus making it easier to extend the use of the device to a large range of stiffnesses.