Patent Application
20080085219
The drawings furnished herewith illustrate a preferred construction of the present invention in which the above advantages and features are clearly disclosed as well as others which will be readily understood from the following description of the illustrated embodiment.
In the drawings:
Referring to
As best seen in
Microfluidic platform 10 further includes a generally U-shaped capillary insert generally designated by the reference numeral 40. It can be appreciated that capillary insert 40 may have other shapes without deviating from the scope of the present invention. Capillary insert 40 includes an inner surface defining a channel or passageway 42 therethrough. Capillary insert 40 includes first end 44 and second end 46, for reasons hereinafter described.
In operation, channel 22 in cartridge 12 is filled with a first sample fluid. Similarly, channel 42 though capillary insert 40 is filled with a second sample fluid. The first and second sample fluids may be identical or different. In addition, the first and second fluids may incorporate particles, molecules, cells or other biological or non-biological objects. Thereafter, first end 44 of capillary insert 40 is inserted into inlet 24 of channel 22 such that channel 22 communicates with first end 42a of passageway 42 through capillary insert 40. Second end 46 of capillary insert 40 is inserted into outlet 26 of channel 22 such that channel 22 communicates with second end 42b of passageway 42 through capillary insert 40,
In order to generate the steady flow of fluid through the closed loop defined by channel 22 and passageway 42, pump 32 is rotated in a first direction as indicated by arrow 48. It is contemplated to rotate pump 32 by the application of an external magnetic field. By way of example, magnetic stirrer 50 may be used, but other types of magnetic sources such as microelectrodes or microcoils may be used without deviating from the scope of the present invention.
Magnetic stirrer 50 includes upper surface 52 for receiving microfluidic platform 10 thereon. As is conventional, magnetic stirrer 50 houses a rotatable bar magnet and includes a control device (not shown) operatively connected to the bar magnet for rotating the bar magnet about central axis at a user selected frequency. An input device such as a rotatable knob may be provided to allow a user to input the selected frequency. Upon actuation of magnetic stirrer 50, the bar magnet magnetically couples and rotates bar 34, and hence, the impeller or disc operatively connected thereto. It can be appreciated that fluid entering pump cavity 30 through the axis of post 34 is urged through channel 22 in a direction generally indicated by arrows 56a-56c due to centrifugal force. Further, since microfluidic platform 10 defines a closed loop with an integrated pump, the resistance of channel 22 and passageway 42 exert the only opposition to the fluid flow. In other words, the fluids flow through channel 22 and passageway 42 without back pressure.
Once fluids in channel 22 and passageway 42 have re-circulated several times and a mixture has been formed, capillary insert 40 may be removed from cartridge 12 with a portion of the mixture or sample contained therein. Thereafter, capillary insert 40 may be interconnected to a second cartridge, in the manner heretofore described, in order to analyze the sample or to perform a second reaction. It can be appreciated that microfluidic platform 10 solves three major problems when working with closed loop systems within microfluidic devices, namely: (1) the filling of a closed loop within a microfluidic device without bubbles; (2) the introduction of a sample into a closed loop without sample loss or dilution in connectors and tubing; and (3) the extraction of a sample and the handling it at the macro scale.
Referring to
It is contemplated to position sensor 58 in close proximity to channel 22 in cartridge 12. Sensor 58 may take the form of an optical sensor, an enzymatic sensor, an electrostatic sensor, or the like. It can be appreciated that sensor 58 may be used to monitor a predetermined parameter of the sample flowing through channel 22.
Referring to
Channels 72 and 74 are generally U-shaped and include central portions 76 and 78, respectively, that communicate with each other. Channel 72 includes inlet 80 and outlet 82. Inlet 80 and outlet 82 communicate with upper surface 84 of cartridge 62. In addition, channel 72 includes an enlarged pump receiving cavity 86 that communicates with inlet 80. Pump receiving cavity 86 is adapted for receiving pump 88 therein. Pump 88 may take the form of a rotatable impeller incorporating a bar of magnetically attractable material, e.g., a ferromagnetic stainless steel bar 90. Alternatively, pump 88 make take the form of a disc pump incorporating a ferromagnetic stainless steel bar (same dimensions and material as the one used as an impeller) embedded in a polymer disc fabricated from a material such as isoobornylacrylate (IBA). The impeller or disc is rotatably mounted on support post 92 in axial symmetry.
Channel 74 includes inlet 94 and outlet 96. Inlet 94 and outlet 96 communicate with upper surface 84 of cartridge 62. In addition, channel 74 includes an enlarged pump receiving cavity 98 that communicates with inlet 94. Pump receiving cavity 98 is adapted for receiving pump 100 therein. Pump 100 may take the form of a rotatable impeller incorporating a bar of magnetically attractable material, e.g., a ferromagnetic stainless steel bar 102. Alternatively, pump 100 make take the form of a disc pump incorporating a ferromagnetic stainless steel bar (same dimensions and material as the one used as an impeller) embedded in a polymer disc fabricated from a material such as isoobornylacrylate (IBA). It is noted that the disc may by fabricated from a ferromagnetic material such that the disc rotates in response to ferromagnetic hysteresis or from a conductive material such that the disc rotates in response to electromagnetic induction. The impeller or disc is rotatably mounted on support post 104 in axial symmetry.
Microfluidic platform 60 further includes first and second generally U-shaped capillary inserts 106 and 108, respectively. It can be appreciated that capillary inserts 106 and 108 may have other shapes without deviating from the scope of the present invention. Capillary inserts 106 and 108 include inner surfaces defining corresponding channels or passageways 110 and 112, respectively, therethrough. Capillary inserts 106 and 108 include first ends 114 and 116, respectively, and second ends 118 and 120, respectively, for reasons hereinafter described.
In operation, channels 72 and 74 in cartridge 62 are filled with a first sample fluid. Similarly, passageways 110 and 112 though capillary inserts 106 and 108, respectively, are filled with corresponding second and third sample fluids, respectively. The first, second and third sample fluids may be identical or different. In addition, the first, second and third fluids may incorporate particles, molecules, cells or other biological or non-biological objects. Thereafter, first end 114 of capillary insert 106 is inserted into inlet 80 of channel 72 such that channel 72 communicates with a first end of passageway 110 through capillary insert 106. Second end 118 of capillary insert 106 is inserted into outlet 82 of channel 72 such that channel 72 communicates with a second end of passageway 110 through capillary insert 106. In addition, first end 116 of capillary insert 108 is inserted into inlet 94 of channel 74 such that channel 74 communicates with a first end of passageway 112 through capillary insert 108. Second end 120 of capillary insert 108 is inserted into outlet 96 of channel 74 such that channel 74 communicates with a second end of passageway 112 through capillary insert 108. As described, capillary insert 106 connects inlet 80 and outlet 82 of channel 72 and capillary insert 108 connects inlet 94 and outlet 96 of channel 74. As such, channels 72 and 74 and passageways 110 and 112 define a closed loop and create a circulatory system.
In order to generate the steady flow of fluid through the loop defined by channel 72 and passageway 110, pump 88 is rotated in a first direction as indicated by arrow 122. It is contemplated to rotate pump 88 by the application of an external magnetic field. By way of example, magnetic stirrer 50 may be used, but other types of magnetic sources such as microelectrodes or microcoils may be used without deviating from the scope of the present invention.
Magnetic stirrer 50 includes upper surface 52 for receiving microfluidic platform 60 thereon. As is conventional, magnetic stirrer 50 houses a rotatable bar magnet and includes a control device (not shown) operatively connected to the bar magnet for rotating the bar magnet about central axis at a user selected frequency. An input device such as a rotatable knob may be provided to allow a user to input the selected frequency. Upon actuation of magnetic stirrer 50, the bar magnet magnetically couples and rotates bar 90, and hence, the impeller or disc operatively connected thereto. It can be appreciated that fluid entering pump cavity 86 through the axis of post 92 is urged through channel 72 in a direction generally indicated by arrows 124a-124c due to centrifugal force.
In order to generate the steady flow of fluid through the loop defined by channel 74 and passageway 112, pump 100 is rotated in a first direction as indicated by arrow 126. It is contemplated to rotate pump 100 by the application of an external magnetic field. By way of example, magnetic stirrer 50 may be used, but other types of magnetic sources such as microelectrodes or microcoils may be used without deviating from the scope of the present invention.
Upon actuation of magnetic stirrer 50, the bar magnet magnetically couples and rotates bar 102, and hence, the impeller or disc operatively connected thereto. It can be appreciated that fluid entering pump cavity 98 through the axis of post 104 is urged through channel 74 in a direction generally indicated by arrows 128a-128c due to centrifugal force.
Since microfluidic platform 60 defines a closed circulatory system with integrated pumps, the resistances of channel 72 and 74 and of passageways 110 and 112 exert the only opposition to the fluid flow. In other words, the fluids flow through channel 72 and passageway 110 without back pressure and through channel 74 and passageway 112 without back pressure.
Referring to
As best seen in
Magnetic stirrer is activated so as to generate steady fluid flow through the loop defined by channel 72 and passageway 110 and steady fluid flow through the loop defined by channel 74 and passageway 112. Diffusion occurs at the interface the fluid streams flowing through central portions 76 and 78 of channels 72 and 74, respectively, such that the small particles flowing in central portion 78 of channel 74 diffuse in the fluid stream flowing in central portion 76 of channel 72. As a result, the smaller particles are carried in the stream designated by the reference numeral 130 toward capillary insert 106. Once the fluids flowing in channel 72 and passageway 110 and in channel 74 and passageway 112 have been re-circulated several times and a mixture has been formed, capillary insert 106 may be removed from cartridge 62 such that the mixture contained therein contains a sample of small particles. Capillary insert 106 may be interconnected to a second cartridge, in the manner heretofore described, in order to analyze the sample or to perform a second reaction.
Referring to
Channels 152 and 154 communicate along portions 152a and 154a, respectively, thereof at interface 155. Channel 152 includes inlet 160 and outlet 162. Inlet 160 and outlet 162 communicate with upper surface 164 of cartridge 142. In addition, channel 152 includes an enlarged pump receiving cavity 166 that communicates with inlet 160. Pump receiving cavity 166 is adapted for receiving a pump therein. The pump may take the form of a rotatable impeller incorporating a bar of magnetically attractable material, e.g., a ferromagnetic stainless steel bar. Alternatively, the pump may take the form of a disc pump incorporating a ferromagnetic stainless steel bar (same dimensions and material as the one used as an impeller) embedded in a polymer disc fabricated from a material such as isoobomylacrylate (IBA). The impeller or disc is rotatably mounted on a support post in axial symmetry. Channel 152 further includes upstream port 168 and downstream port 170, for reasons hereinafter described.
Channel 154 includes inlet 174 and outlet 176. Inlet 174 and outlet 176 communicate with upper surface 164 of cartridge 142. In addition, channel 154 includes an enlarged pump receiving cavity 178 that communicates with inlet 174. Pump receiving cavity 178 is adapted for receiving a pump therein. The pump may take the form of a rotatable impeller incorporating a bar of magnetically attractable material, e.g., a ferromagnetic stainless steel bar. Alternatively, the pump may take the form of a disc pump incorporating a ferromagnetic stainless steel bar (same dimensions and material as the one used as an impeller) embedded in a polymer disc fabricated from a material such as isoobornylacrylate (IBA). It is noted that the disc may by fabricated from a ferromagnetic material such that the disc rotates in response to ferromagnetic hysteresis or from a conductive material such that the disc rotates in response to electromagnetic induction. The impeller or disc is rotatably mounted on a support post in axial symmetry. Channel 154 further includes upstream port 180 and downstream port 182, for reasons hereinafter described.
Microfluidic platform 140 further includes first and second generally U-shaped capillary inserts 186 and 188, respectively. It can be appreciated that capillary inserts 186 and 188 may have other shapes without deviating from the scope of the present invention. Capillary inserts 186 and 188 include inner surfaces defining corresponding channels or passageways 190 and 192, respectively, therethrough. Capillary inserts 186 and 188 include first ends 194 and 196, respectively, and second ends 198 and 200, respectively, for reasons hereinafter described.
Upstream and downstream ports 168 and 170, respectively, in channel 152 may be fluidly connected by a flow droplet (hereinafter described) or by a generally U-shaped capillary insert generally designated by the reference numeral 202. It can be appreciated that capillary insert 202 may have other shapes without deviating from the scope of the present invention. Capillary insert 202 includes an inner surface defining a channel or passageway 204 therethrough. Capillary insert 202 includes first end 206 and second end 208, for reasons hereinafter described.
Upstream and downstream ports 180 and 182, respectively, in channel 154 may be fluidly connection by a generally U-shaped capillary insert (heretofore described) or by flow droplet generally designated by the reference numeral 210. Flow droplet 210 allows for the fluid flow in channel 154 continue from upstream port 180 into downstream port 182 through inner flow path 212 and provides an access point for selectively extracting or introducing fluid and/or particles out of or into channel 154.
In operation, channels 152 and 154 in cartridge 142 are filled with a first sample fluid. Similarly, passageways 190 and 192 though capillary inserts 186 and 188, respectively, are filled with corresponding second and third sample fluids, respectively. The first, second and third sample fluids may be identical or different. In addition, the first, second and third fluids may incorporate particles, molecules, cells or other biological or non-biological objects. Likewise, passageway 202 through capillary insert 202 is filed with a fourth sample fluid, either identical or different than the first, second and third sample fluids. Thereafter, first end 194 of capillary insert 186 is inserted into inlet 160 of channel 152 such that channel 152 communicates with a first end of passageway 190 through capillary insert 186. Second end 198 of capillary insert 186 is inserted into outlet 162 of channel 152 such that channel 152 communicates with a second end of passageway 190 through capillary insert 186.
In addition, first end 196 of capillary insert 188 is inserted into inlet 174 of channel 154 such that channel 154 communicates with a first end of passageway 192 through capillary insert 188. Second end 200 of capillary insert 188 is inserted into outlet 176 of channel 154 such that channel 154 communicates with a second end of passageway 192 through capillary insert 188. As described, capillary insert 186 connects inlet 160 and outlet 162 of channel 152 and capillary insert 188 connects inlet 174 and outlet 176 of channel 154.
First end 206 of capillary insert 202 is inserted into upstream port 168 of channel 152 such that channel 152 communicates with a first end of passageway 204 through capillary insert 202. Second end 208 of capillary insert 202 is inserted into downstream port 170 of channel 152 such that channel 152 communicates with a second end of passageway 202 through capillary insert 202. Finally, flow droplet 210 is deposited on upper surface 164 of cartridge 142 so as to overlap and communicate with upstream and downstream ports 180 and 182, respectively, of channel 154. The volume of flow droplet 210 may be regulated by the use of a computer controlled valve or the like. Flow droplet 210 provides inner flow path 212 from the fluid forming through channel 154. It can be understood that box 214 may be positioned about flow droplet 210 to isolate flow droplet 210 from the external environment and prevent evaporation and contamination thereof. As described, channels 152 and 154; passageways 190, 192 and 204; and inner flow path 212 define a closed loop and create a circulatory system.
In operation, a magnetic stirrer is activated thereby actuating the pumps in pump cavities 166 and 178. As a result, steady fluid flow is generated through the loop defined by channel 152 and passageways 190 and 202. In addition, steady fluid flow is generated through the loop defined by channel 154, passageway 192 and flow path 212. As heretofore described with respect to microfluidic platform 60, diffusion occurs at the interface the fluid streams flowing through portions 152a and 152a of channels 152 and 154, respectively. Once the fluids flowing in channels 152 and 154, passageway 190, 192 and 204, and flow path 212 have been re-circulated several times and a mixture has been formed, a selected capillary insert 186, 188 or 202 may be removed from cartridge 142. Thereafter, the selected capillary insert may be interconnected to a second cartridge, in the manner heretofore described, in order to analyze the sample or to perform a second reaction on the mixture.
It is further contemplated to extract sample fluid from or introduce sample fluid into the circulatory system of
Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter, which is regarded as the invention.
