Swivel mount for centrifugal microfluidic chip

Patent metadata

Field	Value
Publication number	US-11071985-B2
Application number	US-201515313961-A
Country	US
Kind code	B2
Filing date	May 26, 2015
Priority date	May 26, 2014
Publication date	Jul 27, 2021
Grant date	Jul 27, 2021

Abstract

A centrifugal microfluidic chip mounting, kit and method include a swivel joint permitting a chip to rotate about an axis of the chip in a plane swept by a centrifuge, and a force applicator for controlling an angle of the swivel and for applying a force in proportion to a rotational rate of the centrifuge. The mounting includes: a blade part ( 18 ) that couples to, or defines, a blade ( 10 ) of a centrifuge at a radial distance from a centrifuge axis ( 12 ); a chip part ( 20 ) that holds the chip at an orientation having a normal not perpendicular to the axis; a one degree of freedom (DoF) joint ( 16 ) between the blade part and the chip part; and a force applicator ( 28 ) which bears on the chip part at a fixed set of one or more points, which do not surround, and are not surrounded by, the joint.

First claim

The invention claimed is:

1. A microfluidic chip mounting comprising:
a blade part of, or for coupling to, a blade of a centrifuge, the blade adapted for mounting to the centrifuge for rotation about an axis of the centrifuge, and defining a plane of the centrifuge;
a chip part for holding a planar microfluidic chip;
a one degree of freedom (DoF) joint between the blade part and the chip part, the one DoF joint permitting the chip part to move with respect to the centrifuge blade, the motion including at least a 5° pivot projected onto the plane, the motion having an instant centre of rotation separated from the centrifuge axis by a radial distance; and
a force applicator bearing on the blade part or a rotary part of the centrifuge at one end, and the chip or chip part at a second end, the bearing on the chip or chip part being provided at a fixed set of one or more points for constraining the motion, where the fixed point(s) is/are not concentric with any instant centre of rotation of the pivot motion in the plane.

2. The microfluidic chip mounting of claim 1 wherein the motion is substantially limited to a change in position and orientation of the microfluidic chip within the plane.

3. The microfluidic chip mounting of claim 1 wherein: the motion is substantially limited to pivoting in the plane; or the joint is an axial revolute joint.

4. The microfluidic chip mounting of claim 1 wherein the joint comprises at least two guided features and an arcuate path for the guided features defining a guideway, where the arcuate path includes at least one point having a curvature contributing to the definition of a pivot axis of the joint wherein:
two or more of the guided features are separated from each other;
two or more of the guided features share one or more constraint defined by the guideway;
the motion involves pivoting of the chip in the plane with the guideway defining two or more curvatures at different sections; or
the motion includes radial translation of the chip with respect to the axis of the centrifuge, during at least one part of the motion.

5. The microfluidic chip mounting of claim 1 wherein the joint is provided:
on a blade of the centrifuge;
as a coupler between the chip and the centrifuge blade; or
on a mount between the chip and centrifuge blade.

6. The microfluidic chip mounting of claim 1 further comprising a lever, ratchet, or assembly of simple machines to limit a multiple degree of freedom joint to the one DoF joint, and/or to define the force applicator.

7. The microfluidic chip mounting of claim 1 wherein at one instant during the motion, a centre of mass of the chip part, the axis, and the instant centre of rotation, are not collinear in the projected plane, whereby a centripetal force on the chip part drives the motion, with a magnitude depending on a rotational rate of the centrifuge.

8. The microfluidic chip mounting of claim 1 wherein the force applicator comprises:
a mechanical resistance;
an elastic member; or
a squiggle motor, or a motor based on piezoelectric, electroactive polymeric, shape memory alloy, or smart material assemblages, actuable independently of the centrifuge; or
the chip mounting comprises two or more force applicators.

9. A swivel mounting kit for defining, once assembled, an articulated centrifugal blade for mounting a planar centrifugal microfluidic chip to a centrifuge, the articulated blade having:
a blade part adapted for mounting to the centrifuge for rotation about the axis;
a chip part for holding the chip to the swivel mount so that the chip's plane has its normal parallel to the centrifuge axis, in at least one pose of the chip part;
a one degree of freedom (DoF) joint coupling the blade part and the chip part, the one DoF joint permitting the chip part to move with respect to the centrifuge blade, the motion including at least a 5° pivot projected onto the chip's plane, the motion having an instant centre of rotation separated from the centrifuge axis by a radial distance; and
a force applicator bearing on the blade part or a rotary part of the centrifuge at a first end, and on the chip or chip part at a second end, the second end having a fixed set of one or more points for constraining the motion, where the fixed point(s) is/are not concentric with any instant centre of rotation in the chip's plane defined by the motion.

10. The kit according to claim 9 wherein the swivel mounting once assembled:
allows the motion, which is substantially limited to a change in position and orientation of the microfluidic chip within the chip's plane;
allows the motion, which is substantially limited to pivoting in the chip's plane;
includes the one DoF joint which is an axial revolute joint, or at least a guideway comprising at least two guided features and an arcuate path for the guided features, the arcuate path including at least one point having a curvature contributing to the definition of a pivot axis of the joint;
includes the joint that is provided: on a blade of the centrifuge; as a coupler between the chip and the centrifuge blade; or on a mount between the chip and centrifuge blade;
further includes a lever, ratchet or assembly of simple machines to limit a multiple degree of freedom joint to a one DoF joint, and/or to define the force applicator;
allows the motion, which has, at one instant during the motion, a centre of mass of the chip part, the axis, and the instant centre of rotation, are not collinear in the chip's plane, whereby a centripetal force on the chip part drives the motion, with a magnitude depending on a rotational rate of the centrifuge; or
includes one or more force applicator, each of which comprises:
a mechanical resistance;
an elastic member; or
a squiggle motor, or a motor based on piezoelectric, electroactive polymeric, shape memory alloy, or smart material assemblages, actuable independently of the centrifuge.

11. A method for controlling an angle of a centrifugal planar microfluidic chip in a plane swept by a centrifuge to which the chip is mounted, the method comprising:
providing a chip part mounted to a blade of a centrifuge by a one degree of freedom (DoF) joint so that a chip holder of the chip part is positioned at a radial distance from an axis of the centrifuge, to be swept in a plane of the centrifuge by rotation of the centrifuge about the axis;
mounting a force applicator to the blade and the chip part for constraining a motion of the chip part relative to the blade;
placing the chip in the chip holder of the centrifuge so that a center of mass of the chip part, and the axis, are not collinear with any instant centre of rotation of the one DoF joint projected in the plane; and
controlling a rate of centrifuge rotation to vary an instantaneous centripetal force on the chip part provided by the non-alignment of the centre of mass, axis, and instant centre of rotation.

12. The method of claim 11 :
wherein the motion is:
substantially limited to a change in position and orientation of the microfluidic chip within the plane; or
substantially limited to pivoting in the plane;

wherein the one DoF joint:
is an axial revolute joint;
comprises at least two guided features and an arcuate path for the guided features defining a guideway, where the arcuate path includes at least one point having a curvature contributing to the definition of a pivot axis of the joint;
comprises the at least two guided features and the arcuate path for the guided features defining a guideway, wherein:
two or more of the guided features are separated from each other;
two or more of the guided features share one or more constraint defined by the guideway;

Assignees

• Nat Res Council Canada

Inventors

• Clime Liviu
• Veres Teodor
• Morton Keith

Classifications

• G01N2035/00495

  Centrifuges · CPC title

• B01L9/527 Primary

  for microfluidic devices, e.g. used for lab-on-a-chip · CPC title

• B01L2400/0409

  centrifugal forces · CPC title

• B04B5/0407 Primary

  for liquids contained in receptacles (B04B5/0442 takes precedence) · CPC title

• B01L2200/025

  Align devices or objects to ensure defined positions relative to each other · CPC title