Method and apparatus for sorting particles

A microfluidic method for producing a particle product from a sample having particles, the method comprising:

• flowing the sample as a fluidic stream of particles from an upstream inlet along a first flow path through a first microfluidic flow channel formed in a substrate of a microfluidic particle processing component;
• processing the sample on a particle-by-particle basis to produce a particle product;
• outputting a first portion of the processed sample via a first downstream outlet of the first microfluidic flow channel;
• and
• outputting a second portion of the processed sample via a second downstream outlet of the first microfluidic flow channel,
• wherein the step of processing includes:
• activating a switch component;
• redirecting a single selected particle out of the first flow path of the fluidic stream of particles at a switching region and into a second flow path flowing downstream into the second downstream outlet, and
• deactivating the switch component,
• wherein activating the switch component does not generate a pressure wave that travels upstream to the switching region,
• wherein activating the switch component does not shift the remainder of the fluidic stream of unselected particles from the first flow path flowing downstream into the first downstream outlet, and
• wherein activating the switch component includes using an actuator external to and operatively associated with the microfluidic particle processing component, to activate the switch component;
• and
• further comprising using a reservoir operatively associated with the first microfluidic flow channel to dampen or absorb a transient pressure pulse propagated across the microfluidic channel.

A microfluidic system for sorting particles, the microfluidic system comprising:

• a first microfluidic flow channel formed in a particle processing component substrate having an upstream inlet configured to introduce a fluidic stream having a plurality of particles into the first microfluidic flow channel and downstream outlets configured to output portions of the fluidic stream of particles;
• a detection region located downstream of the inlet, the detection region configured to allow a particle having a predetermined characteristic to be sensed, the sensed particle being one of the plurality of particles in the fluidic stream;
• a switching device located downstream of the detection region, the switching device operatively coupled to the first microfluidic flow channel to deliver a transient pressure pulse in a direction substantially perpendicular to a flow direction of the fluidic stream of particles,
• wherein the transient pressure pulse displaces and separates a selected single sensed particle from the fluidic stream of particles,
• wherein the selected particle is displaced and separated from the fluidic stream of particles in a switching region,
• wherein the fluidic stream of unselected particles flows into a first downstream outlet configured to output a first portion of the fluidic stream of particles,
• wherein the selected particle flows into a second downstream outlet configured to output a second portion of the fluidic stream of particles,
• wherein the transient pressure pulse is not generated downstream of the switching region, and
• further including an actuator for activating the switching device and wherein the actuator is a piezoelectric actuator,
• wherein the particle processing component substrate includes a reservoir adapted for dampening or absorbing the transient pressure pulse propagated across the microfluidic channel.