Arrangement for Detecting Resonance Frequency Shifts

• US 20100013456A1
• Filed: 04/25/2007
• Published: 01/21/2010
• Est. Priority Date: 04/26/2006
• Status: Active Grant

• Current Assignee: NEMS AB - 556632-7143
• Original Assignee: NEMS AB - 556632-7143
• Inventors: Ghatnekar-Nilsson, Sara, Montelius, Lars
• Granted Patent: US 7,966,881 B2
• Time in Patent Office: Days
• US Class Current: 324/76.510
• CPC Class Codes: G01G 3/16 measuring variations of frequency of oscillations of the body

Abstract

The present invention relates to an arrangement (1) for detection of a first resonance frequency (F1), related to a mass (1b′) loaded carrier means (1b), and to compare said first resonance frequency (F1) with a second, as a reference used, resonance frequency (F2), related to said carrier means (1b), by using frequency comparing and/or calculating means (3, 4) to evaluate, by a noted frequency shift (F2-F1), a mass weight (1b′). An array of individual carrier means (1a, 1b . . . 1i) are arranged adjacent to each other, that one or more of said carrier means are allotted different second resonance frequencies, that received resonance frequencies (F1) from said loaded carrier means are received and/or evaluated simultaneously, or at least essentially simultaneously, in a signal receiving and/or processing unit (3) and that said first resonance frequencies (F1) are compared and/or calculated within said calculating means (3, 4) with corresponding resonance frequencies (F2) stored in said unit (3, 4) in a memory (4b) thereof.

Claims

1. An arrangement for detecting a first resonance frequency, associated with a carrier means loaded with an added mass, and comparing said first resonance frequency with a second resonance frequency associated with said carrier means without the added mass, in order to evaluate, based on a noted resonance frequency shift, the mass and/or weight of the added mass, comprising:

(a) an array of individual carrier means in which the individual carrier means are adjacent to each other, wherein one or more of said individual carrier means are characterized by different second resonance frequencies and wherein the individual carrier means are simultaneously illuminated, and

(b) a receiving and/or calculating unit that is capable of simultaneously detecting a total reflected signal comprising a number of first resonance frequencies received from said loaded carrier means, thereby allowing carrier means'"'"' resonance frequencies to be detected simultaneously in a frequency domain, wherein said first resonance frequencies are compared and/or calculated within said receiving and/or calculating unit with corresponding second resonance frequencies stored in said unit and wherein the arrangement detects a first resonance frequency, associated with a carrier means loaded with an added mass, and compares said first resonance frequency with a second resonance frequency, associated with said carrier means without the added mass, in order to evaluate, based on a noted resonance frequency shift, the mass and/or weight of the added mass.

2. An arrangement according to claim 1, wherein an oscillating means generates and/or excites resonance frequencies to said array of carrier means.

3. An arrangement according to claim 2, wherein said oscillating means is related to a frequencies sweeping type.

4. An arrangement according to claim 2, wherein said oscillating means generates and/or excites a fixed frequency, exposing a value exceeding the highest frequency related to the highest basic resonance frequency.

5. An arrangement according to claim 1, wherein said array individual carrier means are cantilevers.

6. An arrangement according to claim 5, wherein the resonance frequency of each cantilever provides a reference frequency that is dependent upon the cantilever'"'"'s dimensions, including width, thickness and/or length, and wherein the cantilever'"'"'s dimensions are within the nanometer range or scale.

7. An arrangement according to claim 5, wherein two or more of said cantilevers have different lengths.

8. An arrangement according to claim 1, wherein said carrier means are illuminated by a light source, such as a laser beam generating source, in such a manner that an illuminating light beam is reflected from an illuminated side portion of a carrier means to said receiving and/or calculating unit, wherein the reflected light beam is detected by a position-sensitive photodiode.

9. An arrangement according to claim 8, wherein said position-sensitive photodiode emits an electrical signal in response to the detected light beam, wherein the electrical signal is dependent on the position and frequency of the carrier means which reflects the illuminating light beam.

10. An arrangement according to claim 1, wherein each frequency shift due to a chance in mass of a carrier means is detected.

11. An arrangement according to claim 1, wherein a mass load and any changes thereof are caused by adsorption of mass to the surface of a carrier means.

12. An arrangement according to claim 1, wherein a mass load and any changes thereof are caused by addition of mass to a carrier means wherein the addition of mass occurs through a controlled interaction.

13. An arrangement according to claim 12, wherein said controlled interaction takes place between the surface of a carrier means and an object possessing mass.

14. An arrangement according to claim 12, wherein said controlled interaction comprises a molecular reaction.

15. An arrangement according to claim 12, wherein said controlled interaction comprises a chemical reaction.

16. An arrangement according to claim 12, wherein said controlled interaction comprises a physical reaction.

17. An arrangement according to claim 1, wherein said individual carrier means are epitaxically fabricated nanowires.

18. An arrangement according to claim 1, wherein the surface of one or more of said individual carrier means is functionalized by attachment of a specific antibody and wherein the added mass is an antigen that is specifically bound by the antibody.

19. A method for probing a molecular, chemical and/or physical interaction comprising

(a) providing an arrangement according to claim 1,

(b) detecting a first resonance frequency, associated with a carrier means loaded with an added mass,

(c) comparing said first resonance frequency with a second resonance frequency, associated with said carrier means without the added mass, and

(d) evaluating, based a noted frequency shift, the mass and/or weight of the added mass,

wherein said molecular, chemical and/or physical interaction takes place on the carrier means.

20. A method according to claim 19, wherein the carrier means is a nanomechanical cantilever.

21. A method according to claim 19, wherein said interaction is the adsorption of mass.

22. A method according to claim 21, wherein the adsorbed mass is an external molecule.