Transducer for microfluid handling system

Abstract

The present invention relates to integrated micro-cantilevers, micro-bridges or micro-membranes in micro-liquid handling systems. Such micro-liquid handling systems provide novel detection mechanisms for monitoring the physical, chemical and biological properties of fluids in such systems. The present invention further relates to micro-cantilever, micro-bridge or micro-membrane type sensors having integrated readout. Such constructions allow laminated flows of different liquids to flow in a channel without mixing, which opens up for new type of experiments and which reduces noise related to the liquid movement. The present invention even further relates to sensors having adjacent or very closely spaced micro-cantilevers, micro-bridges or micro-membranes which can be exposed to different chemical environments at the same time.

1 . A sensor for detecting the presence of a substance in a fluid, said sensor comprising: 
 means for handling the fluid, said handling means comprising an interaction chamber of micrometer dimensions, an inlet and an outlet,    a first flexible member having a surface, said surface holding a substance, wherein the surface holding the substance is at least partly positioned inside the interaction chamber so that at least part of the substance is exposed to the fluid, and    means for detecting a mechanical parameter associated with the first flexible member, said mechanical parameter being related to the presence of the substance in the fluid.    
     
     
         2 . A sensor according to  claim 1 , wherein the first flexible member comprises a cantilever having a first and a second end, wherein the first end is attached to the interaction chamber.  
     
     
         3 . A sensor according to  claim 1 , wherein the first flexible member comprises a bridge having a first and a second end, wherein the first and second ends are attached to the interaction chamber.  
     
     
         4 . A sensor according to  claim 1 , wherein the first flexible member forms part of a boundary defining the interaction chamber.  
     
     
         5 . A sensor according to  claim 1 , wherein the detecting means for detecting the mechanical parameter associated with the first flexible member comprises a piezoresistive element, said piezoresistive element being an integral part of the first flexible member.  
     
     
         6 . A sensor according to  claim 1 , wherein the detecting means for detecting the mechanical parameter associated with the first flexible member comprises a laser, an optical element and a position sensitive photo detector.  
     
     
         7 . A sensor according to  claim 6 , wherein the piezoresistive element forms part of a balanced bridge, such as a Wheatstone bridge.  
     
     
         8 . A sensor according to  claim 1  further comprising an actuator for moving the flexible member relative to the interaction chamber.  
     
     
         9 . A sensor according to  claim 8 , wherein the actuator comprises a piezoelectric element.  
     
     
         10 . A sensor according to  claim 8 , wherein the actuator comprises means for providing an electrostatic induced movement of the flexible member.  
     
     
         11 . A sensor according to  claim 8 , wherein the actuator comprises means for providing a magnetic induced movement of the flexible member.  
     
     
         12 . A sensor according to  claim 8 , wherein the actuator comprises means for providing a thermal induced movement of the flexible member.  
     
     
         13 . A sensor according to  claim 1 , wherein the handling means is fabricated in a material selected from the group consisting of metals, glasses, polymers or semiconductor materials, such as silicon.  
     
     
         14 . A sensor according to  claim 1 , wherein the substance being held by the surface of the first flexible member is selected from the group consisting of metals, polymers, biochemical molecules or micro-biochemical structures.  
     
     
         15 . A sensor according to  claim 1 , further comprising 
 a second flexible member being at least partly positioned inside the interaction chamber so that at least part of the second flexible member is exposed to the fluid, and    means for detecting a mechanical parameter associated with the second flexible member.    
     
     
         16 . A sensor according to  claim 15 , wherein the detecting means comprises a piezoresistive element, said piezoresistive element being an integral part of the second flexible member, and wherein the piezoresistive element forms part of a balanced bridge, such as a Wheatstone bridge.  
     
     
         17 . A sensor for detecting the presence of a substance in a fluid, said sensor comprising: 
 means for handling the fluid, said handling means comprising an interaction chamber, an inlet and an outlet,    a first flexible member having a surface, said surface holding a substance, wherein the surface holding the substance is at least partly positioned inside the interaction chamber so that at least part of the substance is exposed to the fluid, and    means for detecting a mechanical parameter associated with the first flexible member, said mechanical parameter being related to the presence of the substance in the fluid, wherein the detecting means form an integral part of the first flexible member.    
     
     
         18 . A sensor according to  claim 17 , wherein the first flexible member comprises a cantilever having a first and a second end, wherein the first end is attached to the interaction chamber.  
     
     
         19 . A sensor according to  claim 17 , wherein the detecting means for detecting the mechanical parameter associated with the first flexible member comprises a piezoresistive element.  
     
     
         20 . A sensor according to  claim 19 , wherein the piezoresistive element forms part of a balanced bridge, such as a Wheatstone bridge.  
     
     
         21 . A sensor according to  claim 17 , wherein the interaction chamber is of micrometer dimensions.  
     
     
         22 . A sensor according to  claim 18  further comprising an actuator for moving the second end of the cantilever relative to the interaction chamber.  
     
     
         23 . A sensor according to  claim 22 , wherein the actuator comprises a piezoelectric element, said piezoelectric element being an integral part of the cantilever.  
     
     
         24 . A sensor according to  claim 17 , wherein the handling means is fabricated in a material selected from the group consisting of metals, glasses, polymers or semiconductor materials, such as silicon.  
     
     
         25 . A sensor according to  claim 17 , wherein the substance being held by the surface of the first flexible member is selected from the group consisting of metals, polymers, biochemical molecules or micro-biochemical structures.  
     
     
         26 . A sensor according to  claim 17 , further comprising 
 a second flexible member being at least partly positioned inside the interaction chamber so that at least part of the second flexible member is exposed to the fluid, and    means for detecting a mechanical parameter associated with the second flexible member.    
     
     
         27 . A sensor according to  claim 26 , wherein the detecting means comprises a piezoresistive element, said piezoresistive element being an integral part of the second flexible member, and wherein the piezoresistive element forms part of a balanced bridge, such as a Wheatstone bridge.  
     
     
         28 . A sensor for detecting the presence of a substance in a fluid, said sensor comprising: 
 means for handling the fluid, said handling means comprising an interaction chamber, an inlet and an outlet,    a first flexible member having a surface, said surface holding a substance, wherein the surface holding the substance is at least partly positioned inside the interaction chamber so that at least part of the substance is exposed to the fluid, and wherein the first flexible member forms an integral part of the handling means, and    means for detecting a mechanical parameter associated with the first flexible member, said mechanical parameter being related to the presence of the substance in the fluid.    
     
     
         29 . A sensor according to  claim 28 , wherein the first flexible member comprises a cantilever having a first and a second end, wherein the first end is attached to the interaction chamber.  
     
     
         30 . A sensor according to  claim 28 , wherein the detecting means for detecting the mechanical parameter associated with the first flexible member comprises a piezoresistive element, said piezoresistive element being an integral part of the first flexible member.  
     
     
         31 . A sensor according to  claim 30 , wherein the piezoresistive element forms part of a balanced bridge, such as a Wheatstone bridge.  
     
     
         32 . A sensor according to  claim 28 , wherein the detecting means for detecting the mechanical parameter associated with the first flexible member comprises a laser, an optical element and a position sensitive photo detector.  
     
     
         33 . A sensor according to  claim 28  further comprising an actuator for moving the second end of the cantilever relative to the interaction chamber.  
     
     
         34 . A sensor according to  claim 33 , wherein the actuator comprises a piezoelectric element, said piezoelectric element being an integral part of the cantilever.  
     
     
         35 . A sensor according to  claim 28 , wherein the handling means is fabricated in a material selected from the group consisting of metals, glasses, polymers or semiconductor materials, such as silicon, and wherein the interaction chamber is of micrometer dimensions.  
     
     
         36 . A sensor according to  claim 28 , wherein the substance being held by the surface of the first flexible member is selected from the group consisting of metals, polymers, biochemical molecules or micro-biochemical structures.  
     
     
         37 . A sensor according to  claim 28 , further comprising 
 a second flexible member being at least partly positioned inside the interaction chamber so that at least part of the second flexible member is exposed to the fluid, and    means for detecting a mechanical parameter associated with the second flexible member.    
     
     
         38 . A sensor according to  claim 37 , wherein the detecting means comprises a piezoresistive element, said piezoresistive element being an integral part of the second flexible member, and wherein the piezoresistive element forms part of a balanced bridge, such as a Wheatstone bridge.  
     
     
         39 . A sensor for detecting the presence of a substance in a fluid, said sensor comprising: 
 means for handling the fluid, said handling means comprising an interaction chamber, an inlet and an outlet,    a first flexible member having a surface, said surface holding a substance, wherein the surface holding the substance is at least partly positioned inside the interaction chamber so that at least part of the substance is exposed to the fluid, and wherein fabrication of the first flexible member is part of fabrication of the handling means,    means for detecting a mechanical parameter associated with the first flexible member, said mechanical parameter being related to the presence of the substance in the fluid.    
     
     
         40 . A sensor according to  claim 39 , wherein the first flexible member comprises a cantilever having a first and a second end, wherein the first end is attached to the interaction chamber.  
     
     
         41 . A sensor according to  claim 39 , wherein the detecting means for detecting the mechanical parameter associated with the first flexible member comprises a piezoresistive element, said piezoresistive element being an integral part of the first flexible member.  
     
     
         42 . A sensor according to  claim 40  further comprising an actuator for moving the second end of the cantilever relative to the interaction chamber.  
     
     
         43 . A sensor according to  claim 39 , wherein the handling means is fabricated in a material selected from the group consisting of metals, glasses, polymers or semiconductor materials, such as silicon, and wherein the interaction chamber is of micrometer dimensions.  
     
     
         44 . A sensor according to  claim 39 , wherein the substance being held by the surface of the first flexible member is selected from the group consisting of metals, polymers, biochemical molecules or micro-biochemical structures.  
     
     
         45 . A sensor according to  claim 39 , further comprising 
 a second flexible member being at least partly positioned inside the interaction chamber so that at least part of the second flexible member is exposed to the fluid, and    means for detecting a mechanical parameter associated with the second flexible member.    
     
     
         46 . A sensor according to  claim 45 , wherein the detecting means comprises a piezoresistive element, said piezoresistive element being an integral part of the second flexible member, and wherein the piezoresistive element forms part of a balanced bridge, such as a Wheatstone bridge.  
     
     
         47 . A sensor for detecting the presence of a first and a second substance in a fluid, said sensor comprising: 
 means for handling the fluid, said handling means comprising an interaction chamber of micrometer dimensions, an inlet and an outlet,    a first flexible member having a surface, said surface holding a first substance, wherein the surface holding the first substance is at least partly positioned inside the interaction chamber so that at least part of the first substance is exposed to the fluid,    a second flexible member having a surface, said surface holding a second substance, wherein the surface holding the second substance is at least partly positioned inside the interaction chamber so that at least part of the second substance is exposed to the fluid,    a first detecting means for detecting a first mechanical parameter associated with the first flexible member, said first mechanical parameter being related to the presence of the first substance in the fluid, and    a second detecting means for detecting a second mechanical parameter associated with the second flexible member, said second mechanical parameter being related to the presence of the second substance in the fluid.    
     
     
         48 . A sensor according to  claim 47 , wherein each of the first and second flexible members comprises a cantilever having a first and a second end, wherein the first end is attached to the interaction chamber.  
     
     
         49 . A sensor according to  claim 47 , wherein each of the first and second flexible members comprises a bridge having a first and a second end, wherein the first and second ends are attached to the interaction chamber.  
     
     
         50 . A sensor according to  claim 47 , wherein each of the first and second flexible members forms part of a boundary defining the interaction chamber.  
     
     
         51 . A sensor according to  claim 47 , wherein the first detecting means comprises a piezoresistive element, said piezoresistive element being an integral part of the first flexible member.  
     
     
         52 . A sensor according to  claim 47 , wherein the second detecting means comprises a piezoresistive element, said piezoresistive element being an integral part of the second flexible member.  
     
     
         53 . A sensor according to  claim 51 , wherein each of the piezoresistive elements forms part of a balanced bridge, such as a Wheatstone bridge.  
     
     
         54 . A sensor according to  claim 47 , wherein the detecting means for detecting the first and second mechanical parameters associated with the first and second flexible member, respectively, comprises a laser, an optical element and a position sensitive photo detector.  
     
     
         55 . A sensor according to  claim 47  further comprising actuators for moving the first and second flexible members relative to the interaction chamber.  
     
     
         56 . A sensor according to  claim 55 , wherein the actuators comprise piezoelectric elements, said piezoelectric elements being an integral part of the cantilevers.  
     
     
         57 . A sensor according to  claim 55 , wherein the actuators comprise means for providing an electrostatic induced movement of the second end of the cantilevers.  
     
     
         58 . A sensor according to  claim 55 , wherein the actuators comprise means for providing a magnetic induced movement of the second end of the cantilevers.  
     
     
         59 . A sensor according to  claim 55 , wherein the actuators comprise means for providing a thermal induced movement of the second end of the cantilevers.  
     
     
         60 . A sensor according to  claim 47 , wherein the handling means is fabricated in a material selected from the group consisting of metals, glasses, polymers or semiconductor materials, such as silicon.  
     
     
         61 . A sensor according to  claim 47 , wherein the substances being held by the surface of the first and second flexible members are selected from the group consisting of metals, polymers, biochemical molecules or micro-biochemical structures.  
     
     
         62 . A sensor for detecting the presence of a first and a second substance in a moving laminated fluid, said laminated fluid comprising, in a cross section perpendicular to a direction of movement, a first and a second region, said sensor comprising: 
 means for handling the laminated fluid, said handling means comprising an interaction chamber, an inlet and an outlet,    a first flexible member having a surface, said surface holding a first substance, wherein the surface holding the first substance is at least partly positioned inside the interaction chamber so that at least part of the first substance is exposed to the first region of the laminated fluid,    a second flexible member having a surface, said surface holding a second substance, wherein the surface holding the second substance is at least partly positioned inside the interaction chamber so that at least part of the second substance is exposed to the second region of the laminated fluid,    means for detecting a first mechanical parameter associated with the first flexible member, said first mechanical parameter being related to the presence of the first substance in the first region of the fluid, and    means for detecting a second mechanical parameter associated with the second flexible member, said second mechanical parameter being related to the presence of the second substance in the second region of the fluid.    
     
     
         63 . A sensor according to  claim 62 , wherein the detecting means for detecting the first mechanical parameter associated with the first flexible member comprises a piezoresistive element, said piezoresistive element being an integral part of the first flexible member.  
     
     
         64 . A sensor according to  claim 63 , wherein the detecting means for detecting the second mechanical parameter associated with the second flexible member comprises a piezoresistive element, said piezoresistive element being an integral part of the second flexible member.  
     
     
         65 . A sensor according to  claim 62 , wherein the detecting means for detecting the first and second mechanical parameters associated with the first and second flexible member, respectively, comprises a laser, an optical element and a position sensitive photo detector.  
     
     
         66 . A sensor according to  claim 62 , further comprising a first actuator for moving part of the first flexible element relative to the handling means.  
     
     
         67 . A sensor according to  claim 66 , wherein the first actuator comprises a piezoelectric element, said piezoelectric element being an integral part of the first flexible member.  
     
     
         68 . A sensor according to  claim 62 , further comprising a second actuator for moving part of the second flexible element relative to the handling means.  
     
     
         69 . A sensor according to  claim 68 , wherein the second actuator comprises a piezoelectric element, said piezoelectric element being an integral part of the second flexible member.  
     
     
         70 . A sensor according to  claim 62 , wherein the handling means is fabricated in a material selected from the group consisting of metals, glasses, polymers or semiconductor materials, such as silicon.  
     
     
         71 . A sensor according to  claim 62 , wherein the substances being held by the surface of the first and second flexible members are selected from the group consisting of metals, polymers, biochemical molecules or micro-biochemical structures.