Centrifugal microfluidic device

A microfluidic valve comprising:

• a piezoelectric substrate;
• a rotatable platform device on the substrate, the rotatable platform device comprising a platform comprising a microfluidic structure comprising an inlet reservoir in fluid connection via a radially disposed microfluidic channel with an outlet reservoir, the inlet reservoir positioned radially inwardly of the outlet reservoir;
• and
• at least one transducer on the substrate, the transducer being configured to generate a surface acoustic wave that propagates on the surface of the substrate and contacts the rotatable platform device asymmetrically to transfer energy thereto with a lateral distribution to cause rotation of the platform such that when the radial acceleration resulting from rotation of the platform is greater than the capillary force retarding the meniscus of a fluid in the inlet reservoir the fluid passes from the inlet reservoir to the outlet reservoir.

A microfluidic mixer comprising:

• a piezoelectric substrate;
• a rotatable platform device on the substrate, the rotatable platform device comprising a platform comprising a microfluidic structure comprising at least two inlet reservoirs each of which is in fluid connection via a radially disposed microfluidic channel with a common outlet reservoir, the inlet reservoirs positioned radially inwardly of the outlet reservoir;
• and
• at least one transducer on the substrate, the transducer being configured to generate a surface acoustic wave that propagates on the surface of the substrate and contacts the rotatable platform device asymmetrically to transfer energy thereto with a lateral distribution to cause rotation of the platform such that when the radial acceleration resulting from rotation of the platform is greater than the capillary force retarding the meniscus of a fluid in each of the inlet reservoirs each fluid passes from each inlet reservoir to the outlet reservoir.

A microfluidic particle concentrator comprising:

• a piezoelectric substrate;
• a rotatable platform device on the substrate, the rotatable platform device comprising a platform comprising a microfluidic structure comprising at least one radially extending reservoir;
• and
• at least one transducer on the substrate, the transducer being configured to generate a surface acoustic wave that propagates on the surface of the substrate and contacts the rotatable platform device asymmetrically to transfer energy thereto with a lateral distribution to cause rotation of the platform such that particles in a particle laden fluid contained in the radially extending reservoir are concentrated in a region of the reservoir following the rotation.

A method of fabricating a centrifugal microfluidic device, the method comprising:

• providing a piezoelectric substrate;
• forming at least one transducer on the surface of the substrate;
• masking the transducer(s) and a non-hydrophobic region of the surface of the substrate;
• depositing a hydrophobic surface on the surface of the masked substrate;
• removing the masks from the substrate;
• depositing a drop of a hydrophilic liquid on the non-hydrophobic region;
• and
• placing a rotatable platform comprising a microfluidic structure on the drop so as to form a fluid coupling layer between the substrate and the rotatable platform.