Micro-fluidic valve with a colloidal particle element

A microfluidic structure comprising:

• a structure defining an input structure for receiving a microfluidic stream, an output structure for transmitting a microfluidic stream, and a space between said input structure and said output structure;
• a colloidal structure located in said space between said input structure and said output structure;
• and
• means for applying a field to said colloidal structure to manipulate said colloidal structure so as to be able to control the flow of a microfluidic stream between said input structure and said output structure;
• wherein:
• said colloidal structure includes a charged colloidal particle;
• wherein:
• said means for applying a field comprises a first electrode and a second electrode for use in moving said charged colloidal particle between an unblocking location that allows a microfluidic flow between said input structure and said output structure and a blocking location that prevents a microfluidic flow between said input structure and said output structure by electrophoresis.

A microfluidic structure comprising:

• a structure defining an input structure for receiving a microfluidic stream, an output structure for transmitting a microfluidic stream, and a space between said input structure and said output structure;
• a colloidal structure located in said space between said input structure and said output structure;
• and
• means for applying a field to said colloidal structure to manipulate said colloidal structure so as to be able to control the flow of a microfluidic stream between said input structure and said output structure;
• wherein:
• said colloidal structure includes a colloidal particle in which a magnetic dipole will be induced by the application of a magnetic field;
• wherein:
• said means for applying a field comprises means for applying a magnetic field to move said colloidal particle between an unblocking location that allows a microfluidic flow between said input structure and said output structure and a blocking location that prevents a microfluidic flow between said input structure and said output structure by electrophoresis.

A microfluidic structure comprising:

• a structure defining an input structure for receiving a microfluidic stream, an output structure for transmitting a microfluidic stream, and a space between said input structure and said output structure;
• a colloidal structure located in said space between said input structure and said output structure;
• and
• means for applying a field to said colloidal structure to manipulate said colloidal structure so as to be able to control the flow of a microfluidic stream between said input structure and said output structure;
• wherein:
• said colloidal structure includes a colloidal particle in which a magnetic dipole will be induced by the application of a magnetic field;
• wherein:
• said means for applying a field comprises means for producing an optical trap to move a colloidal particle between an unblocking location that allows a microfluidic flow between said input structure and said output structure and a blocking location that prevents a microfluidic flow between said input structure and said output structure by electrophoresis.