Back to results
US 6,923,216 B2Granted
Microfluidic device with ultraphobic surfaces
AssigneeEntegris, Inc.
InventorsCharles W. Extrand, Michael Wright
Life of this patent
Estimating the term…
Abstract
A microfluidic device having durable ultraphobic fluid contact surfaces in the fluid flow channels of the device. The ultraphobic surface generally includes a substrate portion with a multiplicity of projecting regularly shaped microscale or nanoscale asperities disposed in a regular array so that the surface has a predetermined contact line density equal to or greater than a critical contact line density, and so that the ratio of the cross-sectional dimension of the asperities to the spacing dimension of the asperities is less than or equal to 0.1.
Claims26
A microfluidic device comprising:
- a body having at least one microscopic fluid flow channel therein, the microscopic fluid flow channel being defined by a channel wall having a fluid contact surface portion, said fluid contact surface portion comprising a substrate with a multiplicity of substantially uniformly shaped and dimensioned asperities thereon, said asperities arranged in a substantially uniform pattern, each asperity having a cross-sectional dimension and an asperity rise angle relative to the substrate, the asperities spaced apart by a substantially uniform spacing dimension and positioned so that the surface has a contact line density measured in meters of contact line per square meter of surface area equal to or greater than a critical contact line density value “ΛL” determined according to the formula:
- Λ
- L
- =
- -
- P
- γ
-
-
- cos
-
-
- (
- θ
- a
- ,
- 0
- +
- ω
- -
- 90
-
- °
- )
- where P is a predetermined maximum expected fluid pressure value within the fluid flow channel, γ is the surface tension of the liquid, θa,0 is the experimentally measured true advancing contact angle of the liquid on the asperity material in degrees, and ω is the asperity rise angle;
- and wherein the ratio of the cross-sectional dimension of the asperities to the spacing dimension of the asperities is less than or equal to 0.1.
23 more elements
A process of making a microfluidic device comprising steps of:
- forming at least one microscopic fluid flow channel in a body, the fluid flow channel being defined by a channel wall having a fluid contact surface portion;
- and
- disposing a multiplicity of substantially uniformly shaped asperities in a substantially uniform pattern on the fluid contact surface portion, each asperity having a cross-sectional dimension and an asperity rise angle relative to the fluid contact surface, the asperities spaced apart by a substantially uniform spacing dimension and positioned so that the surface has a contact line density measured in meters of contact line per square meter of surface area equal to or greater than a critical contact line density value “ΛL” determined according to the formula:
- Λ
- L
- =
- -
- P
- γ
-
-
- cos
-
-
- (
- θ
- a
- ,
- 0
- +
- ω
- -
- 90
-
- °
- )
- where P is a predetermined maximum expected fluid pressure value within the fluid flow channel, γ is the surface tension of the liquid, θa,0 is the experimentally measured true advancing contact angle of the liquid on the asperity material in degrees, and ω is the asperity rise angle;
- and wherein the ratio of the cross-sectional dimension of the asperities to the spacing dimension of the asperities is less than or equal to 0.1.
25 more elements
A microfludic fluid flow system including at least one microfluidic device, the device comprising:
- a body having at least one microscopic fluid flow channel therein, the microscopic fluid flow channel being defined by a channel wall having a fluid contact surface portion, said fluid contact surface portion comprising a substrate with a multiplicity of substantially uniformly shaped and dimensioned asperities thereon, said asperities arranged in a substantially uniform pattern, each asperity having a cross-sectional dimension and an asperity rise angle relative to the substrate, the asperities spaced apart by a substantially uniform spacing dimension and positioned so that the fluid contact surface portion has a contact line density measured in meters of contact line per square meter of surface area equal to or greater than a critical contact line density value “ΛL” determined according to the formula:
- Λ
- L
- =
- -
- P
- γ
-
-
- cos
-
-
- (
- θ
- a
- ,
- 0
- +
- ω
- -
- 90
-
- °
- )
- where P is a predetermined maximum expected fluid pressure value within the fluid flow channel, γ is the surface tension of the liquid, θa,0 is the experimentally measured true advancing contact angle of the liquid on the asperity material in degrees, and ω is the asperity rise angle;
- and wherein the ratio of the cross-sectional dimension of the asperities to the spacing dimension of the asperities is less than or equal to 0.1.
23 more elements
Dependencies are inferred from the claim text.