Sensor and methods for measuring of concentrations of components in a liquid

• US 7,854,159 B2
• Filed: 06/08/2007
• Issued: 12/21/2010
• Est. Priority Date: 06/08/2006
• Status: Expired due to Fees

• Current Assignee: Technische Universitã¤T Dresden
• Original Assignee: Technische Universitã¤T Dresden
• Inventors: Sorber, Jörg, Günther, Margarita, Gerlach, Gerald
• Primary Examiner(s): Caputo; Lisa M
• Assistant Examiner(s): ROY, PUNAM P
• Application Number:
  US11/811,072
• Publication Number:
  US 20070295061A1
• Time in Patent Office: 1,292 Days
• Field of Search: 435/287.1, 73/614.1, 73/614.7, 73/614.8, 600/345, 600/346, 600/347, 600/348, 600/362, 600/363, 600/364, 600/365, 600/366
• US Class Current: 73/61.41
• CPC Class Codes: G01N 33/487 of liquid biological material

Abstract

A sensor for measuring the concentration of components in a liquid, exhibiting a base body with a deformation body, and a hollow chamber. The hollow chamber is on the one side deformable through the deformation body and on the other side rigidly closed. The hollow chamber is completely filled with a swellable polymeric network, which network exhibits a volume phase transition at a certain concentration of components in the liquid. The liquid can have contact to the polymeric network through at least one opening in at least one of the rigid delimiting sides of the hollow chamber. A mechano electrical transducer detects the deflection of the deformation body. The sensor exhibits a servo device (8) working on the deformation body (3), wherein the servo device (8) can be controlled through a control member with a comparator unit (9) such that the deflection of the deformation body (3) is compensated, wherein the corresponding control signal for the servo device (8) represents the measurement value for the concentration of components in the liquid (1).

Claims

1. A sensor for measuring the concentration of a component in a liquid, exhibiting a base body with a deformation body, a hollow chamber, wherein the hollow chamber on the one side is deformable through the deformation body and on the other side is rigidly closed, wherein the hollow chamber is filled with a swellable polymeric network which exhibits a volume phase transition at a certain concentration of a component in the liquid and through at least one opening in at least one of the rigid delimiting sides of the hollow chamber the liquid can have contact with the swellable polymeric network and wherein a mechano electrical transducer detects the deflection of the deformation body,

characterized in that

the sensor exhibits a servo device (8) contacting, working and exercising a mechanical force on the deformation body (3), wherein the servo device (8) is thus controllable by a control signal of a control member with a comparator unit (9) such that the deflection of the deformation body (3) is compensated by a force of the servo device (8) exerted on the deformation body (3) corresponding to balancing a displacement force of the swellable polymeric network (5) acting on the deformation body (3), and in that the corresponding control signal for the servo device (8) is the measurement value for the concentration of a component in the liquid (1).

2. The sensor according to claim 1, wherein the base body (2) is a semiconductor chip (10), wherein the semiconductor chip (10) surrounds a hollow chamber (6) and is mounted to a support (11).

3. The sensor according to claim 1, wherein the deformation body (3) is locally thinned out as a bending plate or as a membrane.

4. The sensor according to claim 1, wherein the deformation body (3) faces and interacts with one or several piezo resistive resistors (13) operating as mechano electrical transducers (4).

5. The sensor according to claim 1, wherein the deformation body (3) supports a movable electrode of a capacitor arrangement, which movable electrode forms the mechano electrical transducer (4).

6. The sensor according to claim 1, wherein the mechano electrical transducer (4) is integrated into the servo device (8).

7. The sensor according to claim 1, wherein the servo device (8) is a piezo electric element.

8. The sensor according to claim 1, wherein the servo device (8) is an electrodynamic element.

10. The sensor according to claim 1, wherein the swellable polymeric network (5) is located in the hollow chamber (6) and exhibits also a temperature sensitivity in addition to a desired sensitivity relative to a component in the liquid and performs the function of being compressed by the servo device (8).

11. The sensor according to claim 1, wherein the mechano electrical transducer (4) is a measurement device coupled with the servo device (8).

12. The sensor according to claim 1, wherein the swellable polymeric network (5) is applied as a thin layer in the hollow chamber (6) on the deformation body (3).

13. The sensor according to claim 1, wherein the swellable polymeric network (5) is entered as a body in the hollow chamber (6) between the deformation body (3) and the support (11).

15. The sensor according to claim 1, wherein the base body (2) is a semiconductor chip (10), wherein the semiconductor chip (10) surrounds the hollow chamber (6) and is mounted on the support (11), wherein the hollow chamber (6) is coupled to an open volume through openings (7) in the support (11).

9. A sensor for measuring the concentration of a component in a liquid, exhibiting a base body with a deformation body, a hollow chamber, wherein the hollow chamber on the one side is deformable through the deformation body and on the other side is rigidly closed, wherein the hollow chamber is completely filled with a swellable polymeric network which exhibits a volume phase transition at a certain concentration of a component in the liquid and through at least one opening in at least one of the rigid delimiting sides of the hollow chamber the liquid can have contact with the polymeric network and wherein a mechano electrical transducer detects the deflection of the deformation body,

characterized in that

the sensor exhibits a servo device (8) working on the deformation body (3), wherein the servo device (8) is thus controllable through a control member with a comparator unit (9) such that the deflection of the deformation body (3) is compensated, and in that the corresponding control signal for the servo device (8) is the measurement size for the concentration of components in the liquid (1), wherein the servo device (8) interacts with a temperature sensitive polymer network and a heating device.

14. A sensor for measuring the concentration of a component in a liquid, exhibiting a base body with a deformation body, a hollow chamber, wherein the hollow chamber on the one side is deformable through the deformation body and on the other side is rigidly closed, wherein the hollow chamber is completely filled with the swellable polymeric network which exhibits a volume phase transition at a certain concentration of components in the liquid and through at least one opening in at least one of the rigid delimiting sides of the hollow chamber the liquid can have contact with the polymeric network and wherein a mechano electrical transducer detects the deflection of the deformation body,

characterized in that

the sensor exhibits a servo device (8) working on the deformation body (3), wherein the servo device (8) is thus controllable through a control member with a comparator unit (9) such that the deflection of the deformation body (3) is compensated, and in that the corresponding control signal for the servo device (8) is the measurement size for the concentration of components in the liquid (1), wherein the base body (2) is a semiconductor chip (10), wherein the semiconductor chip (10) comprises the hollow chamber (6) and is mounted on a support (11), wherein the support has at least one feed flow (12a) and at least one discharge flow (12b) and wherein the liquid (1) has a continuous contact to the polymeric network (5) through the support (11).

16. A sensor for measuring a concentration of a component in a liquid comprising

a base body (2);

a hollow rigid chamber (6) having one side open and delimited in part by the base body (2);

a swellable polymeric network (5) disposed in and rigidly contained in the hollow rigid chamber (6), wherein the swellable polymeric network (5) has a shiftable face located at the open side of the hollow rigid chamber (6), wherein the swellable polymeric network (5) exhibits a volume phase transition occurring at a certain concentration of a component in a liquid;

a deformation body (3) covering the open side of the hollow rigid chamber (6) and of the shiftable face of the swellable polymeric network (5) for following position changes of the shiftable face;

a signal detector (4, 15, 16) interacting with the deformation body (3) for detecting a displacement of the deformation body (3) at the open side of the hollow rigid chamber (6);

a comparator unit (9) connected to the signal detector (4, 15, 16) for receiving a detection signal of a displacement of the deformation body (3) and for generating a control signal;

a servo device (8) connected to the comparator unit (9) for receiving the control signal from the comparator unit (9) and engaging the deformation body (3) with a force for opposing a displacement of the deformation body (3) and for compensating the displacement of the deformation body (3) and wherein the control signal for the servo device (8) is a measurement value for a concentration of a component in the liquid (1).

17. The sensor according to claim 16 further comprising

a support (11) extending the base body (2) for forming a surrounding of the hollow rigid chamber (6), wherein the base body (2) is a semiconductor;

an opening (7) in the hollow rigid chamber (6) in addition to and outside of the open side of the hollow rigid chamber (6) for accessing the swellable polymeric network (5) such that the liquid (1) can have contact with the swellable polymeric network (5) through the opening (7) in the hollow rigid chamber (6);

a feed flow path (12a) connected to the opening (7) for feeding in a liquid (1);

a discharge flow path (12b) connected to the opening (7) for discharging the liquid (1); and

wherein the liquid (1) has a continuous contact to the swellable polymeric network (5) through the opening (7);

wherein the signal detector (4, 15, 16) is a mechano electrical transducer (4).

18. The sensor according to claim 16 further comprising

a distance spacer (14) formed near an outer periphery of the deformation body (3) for defining a distance from the deformation body (3);

a fixedly positioned disk (15) attached to the distance spacer (14) and forming a first electrode and serving as a fixed reference element of a capacitance evaluation;

a tappet (16) transferring a restoring force from the servo device (8) through the deformation of the deformation body (3) caused by the swellable polymer network (5) and forming a second electrode for accomplishing a capacitance change;

wherein the fixedly positioned disk (15) and the tappet (16) form the signal detector (4, 15, 16).

19. A method for measurement of the concentration of components in a liquid with a sensor comprising the steps:

connecting a comparator unit (9) to a servo device (8);

placing a deformation body (3) onto the servo device (8);

generating a control signal in the comparator unit (9);

delivering the control signal from the comparator unit (9) to the servo device (8) for controlling a force of the servo device (8) interacting with the deformation body (3);

placing a mechano electrical transducer (4) at the deformation body;

connecting the mechano electrical transducer (4) to the comparator unit (9);

delivering a detection signal of the displacement from the mechano electrical transducer (4) to the comparator unit (9);

detecting a displacement of the deformation body (3) with the mechano electrical transducer (4);

compensating the displacement of the deformation body (3);

disposing a swellable polymeric network (5) at the deformation body (3);

shifting the deformation body (3) with the liquid having the component and contacting the swellable polymeric network (5);

surrounding the swellable polymeric network (5) with a hollow rigid chamber (6) having an open side for positioning the deformation body (3), wherein the hollow rigid chamber (6) is filled with the swellable polymeric network (5), which exhibits a volume phase transition at a certain concentration of a component in the liquid (1);

providing an opening (7) in the hollow rigid chamber (6), wherein the liquid has contact to the swellable polymeric network through the opening (7) in the hollow chamber (6);

feeding a liquid with a component to the opening;

employing the control signal for the servo device (8) as a measurement value for a concentration of a component in the liquid (1).