Temperature sensing

Patent metadata

Field	Value
Publication number	US-10054494-B2
Application number	US-201514946940-A
Country	US
Kind code	B2
Filing date	Nov 20, 2015
Priority date	Nov 26, 2014
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

An Apparatus and method are provided for sensing temperature of a sample. Apparatus 2 has a sensor 5 , positionable relative to a sample 3 , which is responsive to temperature of a region of the sample at each position of the sensor. Sensor circuitry 10 provides a response signal indicative of the sensor response at the position of the sensor. Sample-temperature controller 12 controls temperature of sample 3 independently of sensor 5 . Sample-temperature controller 12 effects a time-dependent modulation of the sample temperature such that a time-dependent heat flux is generated between the sample and the sensor at the position of the sensor. Temperature analyzer 11 extracts time-averaged and time-dependent components of the response signal due to the modulation of the sample temperature, and processes the components to produce an output indicative of temperature of the sample at the position of the sensor.

First claim

What is claimed is:

1. An apparatus for sensing temperature of a sample, the apparatus comprising:
a sensor that can be moved into one or more positions, relative to a sample, which is responsive to temperature of a region of the sample at each position of the sensor;
sensor circuitry for providing a response signal indicative of the sensor response at the position of the sensor;
a sample-temperature controller for controlling temperature of the sample independently of the sensor, the sample-temperature controller effecting a time-dependent modulation of the sample-temperature such that a time-dependent heat flux is generated between the sample and the sensor at the position of the sensor; and
a temperature analyzer for extracting time-averaged and time-dependent components of the response signal due to the modulation of the sample-temperature, and for processing the components to produce an output indicative of temperature of the sample at the position of the sensor
wherein the sample-temperature controller comprises a signal generator for generating the modulation signal that controls operation of a heating/cooling channel for varying the temperature of the region of the sample.

2. The apparatus according to claim 1 wherein:
the sample-temperature controller is adapted such that the time-dependent modulation of the sample-temperature comprises a first periodic component having a first frequency; and
the temperature analyzer is adapted to extract from the response signal a first time-dependent component having the first frequency.

3. The apparatus according to claim 2 wherein the temperature analyzer is adapted such that the output is dependent on a magnitude D of the time-averaged component and an amplitude A 1 of the first time-dependent component.

4. The apparatus according to claim 3 wherein the temperature analyzer is adapted such that the output is dependent on a first ratio r 1 of the amplitude A 1 to at least the magnitude D.

5. The apparatus according to claim 4 wherein the first ratio r 1 =A 1 /(D+A 1 ).

6. The apparatus according to claim 4 wherein:
the sensor-temperature controller is operable to adjust the sensor temperature from an ambient temperature TA to an operating temperature Top; and
the temperature analyzer is adapted such that the output is dependent on the first ratio r 1 and (Top-TA).

7. The apparatus according to claim 4 wherein:
the sample-temperature controller is adapted to vary the sample-temperature TS from an ambient temperature TA according to TS=TA+T 0 +T 1 sin(ωt)+T 2 sin(2ωt), where ω is the first frequency, the second frequency is 2ω, and T 0 is a constant; and
the temperature analyzer is adapted such that the output is further dependent on a second ratio r 2 of an amplitude A 2 to at least the magnitude D, where A 2 is an amplitude of the second time-dependent component.

8. The apparatus according to claim 6 wherein the output is dependent on r 1 ×(Top-TA).

9. The apparatus according to claim 8 wherein the first ratio r 1 =A 1 /(D+A 1 ) whereby the output is dependent on (Top-TA)×A 1 /(D+A 1 ).

10. The apparatus according to claim 8 wherein the apparatus is adapted to operate such that D>>A 1 , and wherein the first ratio r 1 =A 1 /D whereby the output is dependent on (Top-TA)×A 1 /D.

11. The apparatus according to claim 2 wherein the sample-temperature controller is adapted to vary the sample temperature TS from an ambient temperature TA according to
TS=TA+T 0+ T 1 sin(ω t ), where ω is the first frequency and T 0 is a constant.

12. The apparatus according to claim 11 wherein the sample-temperature controller is adapted such that T 0 =T 1 .

13. The apparatus according to claim 2 wherein the temperature analyzer includes a low-pass filter for extracting the time-averaged component and a lock-in amplifier for extracting the first time-dependent component.

14. The apparatus according to claim 2 wherein:
the sample-temperature controller is adapted such that the time-dependent modulation of the sample temperature includes a second periodic component having a second frequency; and
the temperature analyzer is adapted to extract from the response signal a second time-dependent component having the second frequency.

15. The apparatus according to claim 1 comprising a sensor-temperature controller for controlling temperature of the sensor independently of the sample.

16. The apparatus according to claim 1 wherein, the apparatus being adapted to operate with the sensor in mechanical contact with the sample at the position.

17. The apparatus according to claim 1 wherein, the apparatus being adapted to operate in a scanning mode wherein the sensor is movable, relative to the sample, through multiple positions, and wherein the temperature analyzer is adapted to produce the output indicative of temperature at each of the positions.

18. The apparatus according to claim 1 wherein the sensor comprises a thermoresistive sensor.

19. The apparatus according to claim 1 wherein the sensor comprises a tip of a microscope probe.

20. The apparatus according to claim 1 further comprising:
a probe;
a position controller for positioning the probe relative to a sample; and
the sensor is provided at the probe tip.

21. A method for sensing temperature of a sample, the method comprising:
positioning a sensor at one or more positions relative to a sample, the sensor being responsive to temperature of a region of the sample at each position of the sensor;
obtaining, via sensor circuitry associated with the sensor, a response signal indicative of the sensor response at the position of the sensor;
controlling temperature of the sample independently of the sensor to effect a time-dependent modulation of the sample-temperature such that a time-dependent heat flux is generated between the sample and the sensor at the position of the sensor;
extracting time-averaged and time-dependent components of the response signal due to the modulation of the sample temperature; and
processing the components to produce an output indicative of temperature of the sample at the position of the sensor
wherein the sample-temperature controller comprises a signal generator for generating the modulation signal that controls operation of a heating/cooling channel for varying the temperature of the region of the sample.

Assignees

• IBM

Inventors

• Gotsmann Bernd
• Menges Fabian
• Riel Heike

Classifications

• G01K3/04 Primary

  in respect of time · CPC title