Methods for forming small-volume electrical contacts and material manipulations with fluidic microchannels

A method of controllably moving material comprising the steps of:

• providing a microchannel device that includes a substrate having first and second channels disposed therein, wherein the second channel has a portion that is adjacent to the first channel in substantially parallel relation thereto;
• coupling said first and second channels with a membranous material that is characterized by an ability to conduct ionic current while inhibiting bulk material flow therethrough;
• providing transport of a first material through said first channel;
• and
• controlling the transport of said first material in said first channel by selectively applying an electric potential across said first and second channels and said membranous material such that the transport of the first material in a portion of said first channel adjacent to said portion of said second channel is substantially inhibited, whereby the concentration of the first material is increased in said first channel.

A method of purifying a material comprising the steps of:

• providing a microchip that includes a substrate having at least first, second, and third channels disposed therein, said second channel having a portion that is adjacent to the first channel and said third channel having a portion that is adjacent to the first channel;
• coupling said first and second channels with a membranous material that is characterized by an ability to conduct charged particles or ions while inhibiting bulk material transport therethrough;
• coupling said first and third channels with a membranous material that is characterized by an ability to conduct charged particles or ions while inhibiting bulk material transport therethrough;
• providing a first material in said first channel;
• providing a second material in said second channel;
• providing a third material in said third channel;
• applying an electrical potential between said first channel and said second channel such that charged particles or ions in the first material are transported through said membranous material into said second channel;
• and
• applying a second electrical potential between said first channel and said third channel such that charged particles or ions in the first material are transported through said membranous material into said third channel.

A device for the manipulation of liquid phase materials, comprising:

• a substrate;
• a first channel formed on said substrate;
• a second channel formed on said substrate;
• a membrane disposed between said first and second channels, said membrane being characterized by an ability to conduct ionic current while inhibiting bulk material transport therethrough;
• and
• means for generating a pressure in said first channel by selectively applying an electric potential between said first channel and said second channel, whereby the first material can be transported in said first channel at a desired flow rate and flow direction.

A method of purifying a material comprising the steps of:

• providing a microchip that includes a substrate having at least first and second channels disposed therein, said second channel having a portion that is adjacent to the first channel, and said first and second channels being substantially coplanar in said substrate;
• coupling said first and second channels with a membranous material that is characterized by an ability to conduct charged particles or ions while inhibiting bulk material transport therethrough, said membranous material being substantially coplanar with said first and second channels;
• providing a first material in said first channel;
• providing a second material in said second channel;
• and
• applying an electrical potential between said first channel and said second channel such that charged particles or ions in the first material are transported through said membranous material into said second channel.

A method of controllably moving material in a microchannel device comprising the steps of:

• providing a microchannel device that includes a substrate having first and second channels disposed therein, said first channel having first and second ends;
• coupling said first and second channels with a membranous material that is characterized by an ability to conduct ionic current while inhibiting bulk material flow therethrough;
• providing a first material for transport in said first channel;
• and
• controlling the transport of the first material in said first channel by selectively applying an electric potential across said first and second channels and said membranous material such that the transport of the first material in a portion of said first channel adjacent to a portion of said second channel is substantially inhibited, whereby the concentration of the first material is increased in said first channel.

A method of controllably moving material in a microchannel device comprising the steps of:

• providing a microchannel device that includes a substrate having first, second, and third channels disposed therein;
• coupling said first and second channels with a first membrane that is characterized by an ability to conduct ionic current while inhibiting bulk material flow therethrough;
• coupling said first and third channels with a second membrane that is characterized by an ability to conduct ionic current while inhibiting bulk material flow therethrough, said third channel being coupled to said first channel at predetermined distance from said second channel along said first channel;
• providing a first material in said first channel;
• and
• generating first and second pressures in said first channel by selectively applying an electric potential between the second channel and the third channel, whereby the first material is transported in said first channel at a desired flow rate and flow direction.

A device for the manipulation of liquid phase materials, comprising:

• a substrate;
• a first channel disposed in said substrate and containing a first material, said first channel having first and second ends;
• an electrode made of a spatially defined electrically conducting material, said electrode being in electrical contact with said first channel at a location along said first channel that is intermediate the first and second ends thereof;
• a coverplate formed of a gas permeable material;
• said coverplate and said substrate being mated together such that the coverplate seals the first channel;
• and
• means for generating a pressure in said first channel by selectively applying an electric potential between the first end of said first channel and said electrode, whereby the first material can be transported in said first channel at a desired flow rate and flow direction.

A device for the manipulation of liquid phase materials, comprising:

• a substrate;
• a first channel formed on said substrate;
• a second channel formed on said substrate;
• a third channel formed on said substrate;
• a first membrane disposed between said first and second channels, said first membrane being characterized by an ability to conduct ionic current while inhibiting bulk material transport therethrough;
• a second membrane disposed between said first and third channels at a predetermined distance from said second channel along said first channel, said second membrane being characterized by an ability to conduct ionic current while inhibiting bulk material transport therethrough;
• and
• means for generating first and second pressures in said first channel by selectively applying an electric potential between said second channel and said third channel, whereby the first material can be transported in said first channel at a desired flow rate and flow direction.

A method of controllably moving material comprising the steps of:

• providing a microchip that includes at least first, second, third, and fourth channels formed in a substrate, each of said channels having a first end in communication with fluidic material, said first, second, third and fourth channels communicating at a first intersection, and said first channel and said second channel having respective first and second electrical contacts disposed between their respective first ends and said first intersection, said electrical contact comprising a membranous material that is characterized by an ability to conduct ionic current while inhibiting bulk material flow therethrough;
• generating a first pressure in said first channel by applying a first electrical potential between said first end of said first channel and the first electrical contact and generating a second pressure in said second channel by applying a second electrical potential between said first end of said second channel and the second electrical contact;
• and
• applying said first and second electrical potentials with a first combination of magnitudes and polarities such that a fluidic material is transported from said first channel to the fourth channel.

A method of controllably moving material comprising the steps of:

• providing a microchip that includes at least first, second, third, and fourth channels formed in a substrate, each of said channels having a first end in communication with fluidic material, said first, second, third and fourth channels communicating at a first intersection, and said third channel and said fourth channel having respective third and fourth electrical contacts disposed between their respective first ends and said first intersection, said electrical contact comprising a membranous material that is characterized by an ability to conduct ionic current while inhibiting bulk material flow therethrough;
• generating a first pressure in said third channel by applying a first electrical potential between said first end of said third channel and the third electrical contact and generating a second pressure in said fourth channel by applying a second electrical potential between said first end of said fourth channel and the fourth electrical contact;
• and
• applying said first and second electrical potentials with a first combination of magnitudes and polarities such that a fluidic material is transported from said first channel to the fourth channel.

A method of controllably moving material comprising the steps of:

• (a) providing a microchip that includes at least first, second, third, and fourth channels formed in a substrate, said first, second, third, and fourth channels having respective first ends in communication with fluidic material, said first, second, third and fourth channels communicating at a first intersection, and having respective first, second, third, and fourth electrical contacts disposed between their respective first ends and said first intersection, said electrical contact comprising a membranous material that is characterized by an ability to conduct ionic current while inhibiting bulk material flow therethrough;
• (b) generating a pressure in said first channel by applying an electrical potential between the first end of said first channel and the first electrical contact, generating a pressure in said second channel by applying an electrical potential between the first end of said second channel and the second electrical contact, and generating a pressure in said third channel by applying an electrical potential between the first end of said third channel and the third electrical contact;
• and
• (c) applying the respective electrical potentials with a first combination of magnitudes and polarities such that a fluidic material is transported from said second channel into the fourth channel.