Substance detection system and substance detection method

Patent metadata

Field	Value
Publication number	US-2019265177-A1
Application number	US-201916409884-A
Country	US
Kind code	A1
Filing date	May 13, 2019
Priority date	Nov 14, 2016
Publication date	Aug 29, 2019
Grant date	—

Abstract

A substance detection system and a substance detection method are provided. The temperature identifying portion identifies a surface temperature of the quartz substrate, based on a difference between a deviation of the fundamental wave frequency from at least any predetermined reference fundamental wave frequency of the reference crystal resonator and the detecting crystal resonator and a deviation of the third harmonic frequency from a predetermined reference third harmonic frequency. The substance identifying portion identifies a temperature at which a contaminant attached to the detecting crystal resonator is desorbed from the detecting crystal resonator to identify the contaminant based on the temperature at which the contaminant is desorbed. The temperature is identified based on a difference between the fundamental wave frequency of the reference crystal resonator and the fundamental wave frequency of the detecting crystal resonator measured by the frequency measuring portion and the temperature identified by the temperature identifying portion.

First claim

1 . A substance detection system, comprising:
a reference crystal resonator and a detecting crystal resonator, formed on a single quartz substrate; an oscillation control portion that sequentially oscillates the reference crystal resonator and the detecting crystal resonator at a fundamental wave frequency and a third harmonic frequency; a frequency measuring portion that measures at least any of (i) fundamental wave frequencies of the reference crystal resonator and the detecting crystal resonator and (ii) third harmonic frequencies of the reference crystal resonator and the detecting crystal resonator; a temperature identifying portion that identifies a surface temperature of the quartz substrate, based on a difference between (i) a deviation of the fundamental wave frequency from at least any predetermined reference fundamental wave frequency of the reference crystal resonator and the detecting crystal resonator and (ii) a deviation of the third harmonic frequency from a predetermined reference third harmonic frequency; and a substance identifying portion that identifies a temperature at which a contaminant attached to the detecting crystal resonator is desorbed from the detecting crystal resonator, so as to identify the contaminant based on the temperature at which the contaminant is desorbed, and the temperature being identified based on (i) at least any of (1) a difference between the fundamental wave frequency of the reference crystal resonator and the fundamental wave frequency of the detecting crystal resonator or (2) a difference between the third harmonic frequency of the reference crystal resonator and the third harmonic frequency of the detecting crystal resonator measured by the frequency measuring portion, and (ii) the temperature identified by the temperature identifying portion.

2 . The substance detection system according to claim 1 , wherein
the oscillation control portion switches whether to oscillate the reference crystal resonator at the fundamental wave frequency or the third harmonic frequency by time sharing.

3 . The substance detection system according to claim 1 , wherein the oscillation control portion includes:
a fundamental wave oscillating portion that oscillates the reference crystal resonator and the detecting crystal resonator at the fundamental wave frequency; a third harmonic oscillating portion that oscillates the reference crystal resonator and the detecting crystal resonator at the third harmonic frequency; a resonator selecting portion that selects any one of the reference crystal resonator and the detecting crystal resonator; and an oscillating-portion selecting portion that selects any one of the fundamental wave oscillating portion and the third harmonic oscillating portion.

4 . The substance detection system according to claim 1 , further comprising:
a heating portion that heats the quartz substrate based on the temperature identified by the temperature identifying portion.

5 . The substance detection system according to claim 4 , further comprising:
a heating control portion that controls a heating amount in the heating portion based on a difference between the temperature identified by the temperature identifying portion and a target temperature.

6 . The substance detection system according to claim 1 , further comprising:
a base substrate, on which the quartz substrate is disposed; and a fixing member that sandwiches the base substrate and the quartz substrate to fix the quartz substrate to the base substrate.

7 . The substance detection system according to claim 6 , further comprising:
a heating portion, formed on an inner layer of the base substrate to heat the quartz substrate.

8 . The substance detection system according to claim 6 , further comprising:
a heating portion, disposed on a side opposite to a side on which the quartz substrate is disposed of the base substrate to heat the quartz substrate.

9 . The substance detection system according to claim 1 , wherein
the substance identifying portion identifies the temperature at which the contaminant is desorbed, based on a variation in the difference between the fundamental wave frequency of the reference crystal resonator and the fundamental wave frequency of the detecting crystal resonator or the difference between the third harmonic frequency of the reference crystal resonator and the third harmonic frequency of the detecting crystal resonator.

10 . The substance detection system according toclaim 1 , further comprising:
a cover member that covers the reference crystal resonator and exposes the detecting crystal resonator.

11 . A substance detection method for detecting a substance using a QCM sensor module including a reference crystal resonator and a detecting crystal resonator formed on a single quartz substrate, the substance detection method comprising:
measuring a reference fundamental wave frequency of an oscillation signal output, while oscillating the reference crystal resonator at a fundamental wave frequency; measuring a detecting fundamental wave frequency of an oscillation signal output, while oscillating the detecting crystal resonator at a fundamental wave frequency; measuring a reference third harmonic frequency of an oscillation signal output, while oscillating the reference crystal resonator at a third harmonic frequency; measuring a detecting third harmonic frequency of an oscillation signal output, while oscillating the detecting crystal resonator at a third harmonic frequency; identifying a surface temperature of the quartz substrate, based on a difference between a deviation of the reference fundamental wave frequency from a predetermined reference fundamental wave frequency and a deviation of the reference third harmonic frequency from a predetermined reference third harmonic frequency; and identifying a temperature at which a contaminant attached to the detecting crystal resonator is desorbed from the detecting crystal resonator, so as to identify the contaminant based on the temperature at which the contaminant is desorbed, the temperature being identified based on a difference between the reference fundamental wave frequency and the detecting fundamental wave frequency, and the identified temperature.

Assignees

• Nihon Dempa Kogyo Co
• Japan Aerospace Exploration

Inventors

• Kukita Hiroyuki
• Wakamatsu Shunichi
• Shiobara Tsuyoshi
• Ishikawa Takayuki
• Miyazaki Eiji
• Tsuchiya Yuta

Classifications

• G01N2291/0426

  Bulk waves, e.g. quartz crystal microbalance, torsional waves · CPC title

• G01N2291/0256

  Adsorption, desorption, surface mass change, e.g. on biosensors · CPC title

• G01N2291/021

  Gases · CPC title

• G01N2291/014

  Resonance or resonant frequency · CPC title

• G01N29/4454

  Signal recognition, e.g. specific values or portions, signal events, signatures · CPC title