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US 2003/0215334 A1Published application
Micropump with heating elements for a pulsed operation
AssigneeRoche Diagnostics Operations, Inc.
InventorsCarlo Effenhauser, Herbert Harttig, Tony Ziegler
Life of this patent
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Abstract
The invention discloses a micropump having heating elements in which an essentially pulsed operation of the heating elements occurs by means of a control unit. The pulsed operation of the heating elements enables an exact control of the flow rate. With the aid of the control unit it is possible to keep the flow rate constant over a long period of days or to change the flow rate rapidly and precisely.
Claims27
Micropump with a heating element comprising
- a fluidic transport element which can be connected to a liquid reservoir and in the connected state makes a fluidic connection between the liquid reservoir and an evaporation area,
- a heating element which is located in an end area of the transport element,
- a control unit for controlling the heating element,
- wherein the control unit controls the heating element by signals in such a manner that the heating element is alternately in a resting phase for a period T1 and in a heating phase for a period T2 and the resting phase and the heating phase alternate essentially periodically resulting in a pulsed operation of the heating element.
1 more element
Micropump as claimed in one of the previous claims,
- which is connected to a liquid reservoir containing a liquid to be transported and the fluidic transport element is at least partially filled with the liquid to be transported.
Method for operating a micropump comprising
- sending a first signal which initiates a heating phase to a heating element such that heat is generated in an end area of a fluidic transport element of a micropump and
- continuing the heating phase for a defined period T2 which is determined by the transmitted signal,
- evaporating at least a portion of a liquid which is located in the end region of the transport element by the generated quantity of heat, whereby
- the essentially completely evaporated liquid escapes from the transport element
- interrupting the heating phase for a period T1 so that the end region of the transport element cools during which
- liquid flows on into the end of the transport element and
- transmitting a second signal after the period T1 so that a new heating phase is initiated and liquid is evaporated,
- repeating the above steps so that the inflow of liquid into the end of the transport element sets a certain flow rate.
5 more elements
Dependencies are inferred from the claim text.