Method and apparatus for sorting particles

A particle sorting system, comprising:

• a first duct for conveying a stream of suspended particles confined in a carrier liquid, comprising an inlet, a first outlet and a second outlet;
• a sensor for sensing a predetermined characteristic in a particle;
• a first side channel in communication with the first duct;
• a sealed actuator chamber positioned adjacent to the first side channel, wherein the carrier fluid forms a meniscus in the first side channel to separate the sealed chamber from the carrier fluid;
• an actuator for modifying the pressure in the sealed actuator chamber to deflect the meniscus when the sensor senses said predetermined characteristic, whereby the deflection of the meniscus creates a transient flow in the first duct which deflects particle having said predetermined characteristic to flow into the second outlet while particles that do not have said predetermined characteristic flow into the first outlet;
• and
• a buffer for absorbing the transient flow in the first duct.

A particle sorting system, comprising:

• a duct for conveying a stream of particles in a carrier fluid, comprising an inlet, a first outlet and a second outlet, wherein the particles normally flow from the inlet into the first outlet;
• a sensor for sensing a predetermined characteristic in a particle;
• an actuator for selectively applying a pressure pulse to the suspension to deflect a particle in the stream of particles into the second outlet when said predetermined characteristic is detected;
• and
• a buffer for absorbing the pressure pulse.

A particle sorting system, comprising:

• a duct for conveying a stream of suspended particles confined in a carrier fluid, comprising an inlet, a first outlet and a second outlet, wherein the particles normally flow from the inlet into the first outlet;
• a sensor for sensing a predetermined characteristic in a particle;
• an actuator for selectively applying a pressure pulse to the stream of suspended particles to deflect a particle in the stream of particles when said predetermined characteristic is detected, causing it to flow into the second outlet;
• and
• a buffer for absorbing the pressure pulse, wherein the buffer comprises a side channel in communication with the duct, a sealed buffer chamber adjacent to the side channel and a meniscus formed by the carrier fluid at an interface between the sealed chamber and the side channel.

A particle sorting system, comprising

• a first duct for conveying a stream of suspended particles confined in a carrier liquid, comprising an inlet, a first outlet and a second outlet;
• a sensor for sensing a predetermined characteristic in a particle;
• a side channel in communication with the first duct;
• a sealed chamber positioned adjacent to the side channel, wherein the carrier fluid forms a first meniscus in the side channel to separate the sealed chamber from the sealed chamber;
• an actuator for modifying the pressure in the sealed chamber to deflect the first meniscus when the sensor senses said predetermined characteristic, whereby the deflection of the meniscus causes a particle having said predetermined characteristic to flow into the second outlet while particles that do not have said predetermined characteristic flow into the first outlet;
• and
• a buffer for absorbing the pressure pulse, wherein the buffer comprises a side channel in communication with the duct, a sealed chamber adjacent to the side channel and a first meniscus formed by the carrier fluid at an interface between the sealed chamber and the side channel.

A particle sorting system for sorting particles suspended in a liquid, comprising:

• an inlet duct through which flows a liquid containing particles having a predetermined characteristic and particles not having a predetermined characteristic,
• wherein
• a) the inlet duct branches into a plurality of measurement channels which are operated in parallel and simultaneously fed with the liquid, each measurement channel having a sorting module and two outlet channels, and each sorting module having a switch unit for distribution of particles having a predetermined characteristic and particles not having a predetermined characteristic to said two different outlet channel,
• b) each switch unit comprising at least one sensor which detects and classifies the particles having the predetermined characteristic, a side passage in communication with the inlet duct, a sealed chamber adjacent to and separated from the side passage by a meniscus formed by the liquid and an actuator controlled by each said sensor arranged on each said switch unit for selectively deflecting the meniscus to deflect a particle having the predetermined characteristic into one of said outlet channels;
• and
• c) each of said two outlet channels on each measurement channel is connected to a separate summing channel for the particles having a predetermined characteristic and particles not having a predetermined characteristic selectively distributed to it.

A particle sorting system for sorting particles suspended in a liquid, comprising:

• an inlet duct through which flows a liquid containing particles having a predetermined characteristic and particles not having a predetermined characteristic,
• wherein
• a) the inlet duct branches into a plurality of channels which are operated in parallel and simultaneously fed with the liquid, each channel having a sorting module and two outlet channels, and each sorting module having a switch unit for distribution of particles having a first predetermined characteristic and particles not having the first predetermined characteristic between said two different outlet channels,
• b) each sorting module comprising at least one sensor which detects and classifies the particles having the first predetermined characteristic, and an actuator controlled by each of said sensor arranged on each said switch unit for selectively deflecting a particle having the first predetermined characteristic into one of said outlet channels;
• c) each of said two outlet channels on each sorting module is connected to a separate summing channel for the particles having the first predetermined characteristic and particles not having the first predetermined characteristic selectively distributed to it;
• and
• d) at least one secondary sorting module connected to the summing channel for the particles having the first predetermined characteristic, each of said secondary sorting modules having a first outlet channel and a second outlet channel, a detector for sensing particles and a switch unit for selectively deflecting a particle having a second predetermined characteristic into one of said outlet channels based on a second predetermined characteristic.

A method of sorting small particles comprising the steps of:

• providing a closed duct having an inlet and a fork at which the duct separates into two branch ducts;
• conducting a stream of liquid into the duct inlet with a stream of particles suspended therein, the particle stream normally flowing through a first one of the branch ducts;
• surrounding the stream of liquid with a particle free enveloping current of liquid to produce substantially laminar flow;
• providing a measurement station along the closed duct upstream of the fork for sensing a predetermined property of particles in the stream and for producing a signal when the property is sensed;
• providing an actuator for applying a pressure on the liquid;
• and
• providing means for buffering pressure variations in the liquid, the pressure buffering means co-operating with the pressure applying means to result in a momentary deflection of the liquid streaming through the duct substantially perpendicular to the normal direction of flow from the point where the pressure is applied towards the point where the pressure is buffered, causing the specific particle having the predetermined property to flow into the second branch duct without eliminating the laminar flow.