Capacitance sensor with asynchronous ring oscillator circuit

• US 20080087542A1
• Filed: 10/10/2007
• Published: 04/17/2008
• Est. Priority Date: 02/12/2002
• Status: Abandoned Application

• Current Assignee: Cambridge University (Government of United Kingdom), Seiko Epson Corporation (Seiko Group)
• Original Assignee: Cambridge University (Government of United Kingdom), Seiko Epson Corporation (Seiko Group)
• Inventors: Moore, Simon, Islam, Mujahid
• Application Number:
  US11/907,221
• Publication Number:
  US 20080087542A1
• Time in Patent Office: Days
• US Class Current: 204/403.01
• CPC Class Codes: G01N 27/228 Circuits therefor measuring capacitance per se G01R27/26
• CPC Class Codes: G01N 27/3276 being a hybridisation with immobilised receptors using a FET type sensor G01N27/4145; concerning the hybridisation C12Q1/68
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing

Abstract

A capacitance sensor comprises an asynchronous ring first in first out (FIFO) oscillator circuit having an electrode for receiving a sample for analysis. A sample placed into contact with the electrode causes a change in capacitance at the electrode which gives rise to a change in the oscillation frequency of the ring. This change in oscillation frequency can be used to identify the sample.

Claims

1. A biosensor comprising:

a first electrode;

a second electrode;

a plurality of DNA strands disposed between the first and second electrodes; and

a circuit electrically connected to the first electrode, the circuit including a thin film transistor that includes an organic polymer.

2. The biosensor according to claim 1, the circuit including an inverter circuit.

3. The biosensor according to claim 1, the circuit including a plurality of inverter circuits that are electrically connected in a ring.

4. The biosensor according to claim 1, the circuit including a FIFO element.

5. The biosensor according to claim 1, the circuit including a plurality of FIFO elements that are electrically connected in a ring.

6. The biosensor according to claim 1, the circuit including an asynchronous oscillator circuit.

7. The biosensor according to claim 1, the circuit including an insulator region including an organic material.

8. The biosensor according to claim 1, the circuit including an interconnection including a conductive organic material.

9. The biosensor according to claim 1, further comprising:

a counter electrically connected to the circuit.

10. The biosensor according to claim 9, further comprising:

a timer electrically connected to the counter.

11. The biosensor according to claim 10, the counter being configured to count an oscillation cycle of the circuit during a count period determined by a clock signal received from the timer.

12. The biosensor according to claim 9, further comprising:

a register block that is configured to store a count number provided by the counter.

13. The biosensor according to claim 12, further comprising:

a microcontroller that is configured to process the count number stored in the register block.

14. A biosensor comprising:

a first electrode;

a second electrode;

a plurality of DNA strands disposed between the first and second electrodes; and

a circuit electrically connected to the first electrode, the circuit including a thin film transistor that includes a semiconductor organic material, the circuit including an insulator region including an insulator organic material, the circuit including an interconnection including a conductive organic material.

15. A biosensor comprising:

an electrode;

a plurality of DNA strands disposed on the electrode; and

a circuit electrically connected to the electrode, the circuit including a thin film transistor that includes a semiconductor organic material.