WO2019054773A1

WO2019054773A1 - Sensor having enhanced detection capability

Info

Publication number: WO2019054773A1
Application number: PCT/KR2018/010758
Authority: WO
Inventors: 이상돈
Original assignee: 주식회사 지파랑
Priority date: 2017-09-13
Filing date: 2018-09-13
Publication date: 2019-03-21

Abstract

A sensor according to the present embodiment comprises: a light provision unit comprising a light-emitting device for providing an optical stimulus, and a first controllable power source for providing driving power to the light-emitting device; a light detection unit comprising a light-receiving device for detecting an optical response to the optical stimulus and then outputting same as an electric signal, and a second controllable power source for providing driving power to the light-receiving device; and a control unit for controlling the driving powers provided by the first controllable power source and the second controllable power source.

Description

Sensors with improved detection capability

The technology relates to sensors.

The sensor detects the presence or concentration of the target to be detected. Typical sensors detect targets within the limit of detection (LOD), and are generally not detectable beyond the limits of detection.

Various efforts have been made to extend the detection region in which the target can be detected. In particular, a configuration using positive feedback to extend the detection limit has been developed. According to this technique, the area where the target can be detected increases dramatically. However, since an operational amplifier (OP-AMP) having a positive feedback structure drives the LED directly, it operates stably even at a high voltage, An operational amplifier must be used, and the power consumed therefrom is increased.

The present embodiment is for solving the above-mentioned problem. That is, a problem to be solved by the present embodiment is to provide a sensor that uses a relatively low price device, reduces power consumption, and increases the detection limit.

The sensor according to the present embodiment includes an actuator that provides a stimulus, a stimulus providing unit that includes a first controllable power source that provides a driving power to the actuator, and a controller that detects a response to the stimulus, And a second controllable power source for providing driving power to the detecting element, and a first control power supply and a second control power supply corresponding to a digital code, And a control unit for controlling the driving power.

The sensor according to the present embodiment has an advantage that it has an extended detection limit compared to the prior art.

1 is a block diagram showing an outline of a sensor according to the present embodiment.

2 is a block diagram illustrating an overview of a sensor that provides optical stimulation and detects an optical response.

Fig. 3 (a) and Fig. 3 (b) are block diagrams showing the outline of the detection unit.

4 (a) and 4 (b) are block diagrams showing the outline of the control unit.

5 is a block diagram showing an outline of a sensor according to another embodiment.

Figs. 6 (a) and 6 (b) schematically show the current-voltage curve of the light-receiving element of the sensor. Fig.

7 (a) is a view schematically showing a current-voltage curve of a light-receiving element according to another embodiment of the sensor operation, and Fig. 7 (b) And detecting the concentration. Fig.

FIG. 8 is a diagram illustrating the result of measuring the optical response through the sensor according to the present embodiment.

Figure 9 is a plot showing the optical response to 1 nM BSA and the ratio of optical response to deionized water.

10 is a diagram showing a result of detection of a target as an embodiment of a sensor in which a negative resistance region is not formed.

The description of the present invention is merely an example for structural or functional explanation, and the scope of the present invention should not be construed as being limited by the embodiments described in the text. That is, the embodiments are to be construed as being variously embodied and having various forms, so that the scope of the present invention should be understood to include equivalents capable of realizing technical ideas.

Meanwhile, the meaning of the terms described in the present application should be understood as follows.

It should be understood that the singular " include " or " have " are to be construed as including a stated feature, number, step, operation, component, It is to be understood that the combination is intended to specify that it is present and not to preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

The drawings referred to for explaining embodiments of the present disclosure are exaggerated in size, height, thickness, and the like intentionally for convenience of explanation and understanding, and are not enlarged or reduced in proportion. In addition, any of the components shown in the drawings may be intentionally reduced, and other components may be intentionally enlarged.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Terms such as those defined in commonly used dictionaries should be interpreted to be consistent with the meanings in the context of the relevant art and can not be construed as having ideal or overly formal meaning unless explicitly defined in the present application .

Hereinafter, the sensor 1 according to the present embodiment will be described with reference to the accompanying drawings. 1 is a block diagram showing an outline of a sensor according to an embodiment. Referring to FIG. 1, a sensor according to an embodiment of the present invention includes: (1) an actuator for providing a stimulus to a medium; a first controllable power source for providing a driving power to the actuator; a detection device (det) for detecting a response to a stimulus, a second control for providing driving power to the detection element (det), and a control unit A detection unit 200 including a second controllable power source 210 and a control unit 300 for controlling power provided by either the first control power source 110 or the second control power source 210 .

The actuator act may be supplied with driving power from the first control power source 110 to provide a stimulus to the medium M containing the target. In one embodiment, the actuator act may be an optical actuator, and the optical actuator is provided with drive power to apply an optical stimulus to the medium M containing the detection target. Hereinafter, an actuator that provides any one of ultraviolet light, visible light, infrared light, and laser light is defined as an optical actuator. For example, the optical actuator may be implemented by a light emitting diode (LED), a laser diode (LD), or the like, which receives a bias and provides light.

The light emitting diode (LED) can emit visible light, ultraviolet light, or infrared light in a wavelength band, and the laser diode can emit laser light having a specific band in the range of 270 nm to 3330 nm. It is preferable that the optical system is provided with a sensing system so as to irradiate light having a suitable band according to characteristics of a substance to be detected.

In another embodiment, the actuator may include a non-optical stimulus such as a sonic wave, an ultrasonic wave, a radio frequency (RF), a radiation, a magnetic field, and an electric field And the non-optical actuator applies a non-optical stimulus to the medium 200 containing the detection substance by being biased. Hereinafter, an actuator that provides any one of a sonic wave, an ultrasonic wave, a radio frequency (RF), a radiation, a magnetic field, and an electric field is defined as a non-optical actuator . Non-optical actuators can be implemented with devices capable of applying non-optical stimuli such as sonic waves, ultrasound, RF, radiation, magnetic fields or electric fields.

The optical actuator applies an optical stimulus and the non-optical actuator applies a non-optical stimulus so that each actuator performs a common function of being biased and providing a corresponding degree of stimulus.

The detection unit 200 includes a second control power source 210 and a detection device det that receives drive power from the second control power source 210 and detects a reaction of the medium M with respect to a stimulus do. In one embodiment, the detecting element det may be a photodetecting element for detecting the optical response of the medium M and outputting it as an electrical signal. For example, the sensing element may be a photodiode, a phototransistor, and a PMT (PhotoMultiplier Tube), is supplied with driving power from a second control power supply 210, detects the optical response of the medium and generates a corresponding electrical signal .

In another embodiment, the detecting element det may be a non-optical detecting element which detects the non-optical response of the medium and outputs an electrical signal. As an example, the non-optical detecting element may be a sensor for detecting a sound wave provided to the medium M, a medium for the ultrasonic wave and a physical change of the target, and an electric field provided to the medium M, It may be a sensor that detects electrical, magnetic, or physical changes. In addition, for example, the non-optical detecting element may be a sensor for detecting the medium for the radiation applied to the medium M and the physical change of the target, the transmittance of the radiation, and the like.

Hereinafter, for convenience of explanation, an optical stimulus is applied to the medium M by an optical actuator as illustrated in FIG. 2, and the detection unit 200 mainly focuses on an embodiment for detecting an optical response to an optical stimulus. However, this does not exclude embodiments such as detecting an optical reaction by providing radioactivity as a non-optical stimulus to the medium, or detecting an electric field decay rate as a non-optical reaction by providing an electric field as a non-optical stimulus to the medium. And is not intended to limit the scope of the invention in any way.

Referring to FIG. 2, a light emitting device (LED) is provided with a bias current from a first control power supply 110 to provide an optical stimulus to the medium M, and the intensity of the optical stimulus corresponds to the provided bias current . Also, the light emitting device (LED) may have a threshold value and may not provide an optical stimulus if a voltage or current below the threshold is provided. As another example, the light emitting element can irradiate laser light having a specific band in the 270 nm to 3330 nm band.

The optical stimulus is provided to the detection target. The target may be included in the medium M as an example. When the target is provided with an optical stimulus, the target is optically responsive. In one example, the optical reaction may be any one or more of light absorption, phosphorescence, scattering, reflection, and floodlighting. As an example of the optical reaction, BSA (Bovine Serum Albumin) has a characteristic of absorbing light of 270 to 280 nm. Therefore, when a laser beam having a wavelength of 275 nm is irradiated to a medium containing BSA, the BSA performs an optical reaction to absorb the applied light to the applied optical stimulus.

However, this is merely an example for explanation, and optical responses to optical stimuli generated depending on the detection substance and the detection substance and the optical stimulus to be applied to the detection substance may be different.

The light receiving element PD detects the optical response and outputs it as a corresponding electrical signal. In one embodiment, the light receiving element PD may be provided with a bias current from a second control power supply 210 that provides drive power.

The sensor according to this embodiment detects the optical response provided by the medium while sweeping the bias current provided to the light emitting element (LED) and the light receiving element (PD). As will be described later, the photodetector 300 may have a negative resistance characteristic as the bias current changes.

The sensor may further include a voltage clamping element 220 connected in parallel with the light receiving element PD. Due to the characteristics of the photodiode driven in the reverse direction, it is necessary to operate near the breakdown voltage so that a sufficiently large current can be obtained from the photodiode PD. However, yielding due to reverse bias may occur, which may cause a problem in the reliability of the photodiode operation.

The voltage clamping element 220 for clamping the voltage value applied to the light receiving element by preventing the voltage value applied to the light receiving element from increasing beyond the target voltage is provided in parallel to the photodiode PD to provide a sufficiently large current, . The voltage clamping element prevents the voltage value provided at both ends from rising above a predetermined clamping voltage value. Therefore, a voltage clamping element having a predetermined clamping voltage can be connected to the photodiode in parallel to prevent reverse voltage from being applied to the photodiode so that the reliability of the photodiode becomes problematic.

In one embodiment, the voltage clamping element may be implemented as a zener diode utilizing the zener breakdown phenomenon as illustrated in Figure 3 (a). When a voltage equal to or higher than the Zener breakdown voltage is applied to the Zener diode, the Zener breakdown phenomenon occurs and the reverse current can not be blocked. Therefore, current flows and the voltage is clamped to prevent a voltage exceeding the Zener breakdown voltage from being applied across the Zener diode. Thus, connecting the zener diode in parallel with the photodiode provides the advantage that the reliability of the photodiode can provide sufficient current without applying a voltage above the problematic voltage.

The sensor may further include a resistor 230 connected in parallel with the light receiving element PD as illustrated in Fig. 3 (b). For example, when the optical response of the target is detected and the voltage across the light receiving element changes from 0 to several tens V, the current value changes by approximately several tens nA, and the average resistance value during the corresponding period is approximately several to several tens of GΩ do.

If the resistance of one resistor is larger than the resistance of other resistors, the equivalent resistance value of the resistors connected in parallel is approximated to the smaller resistance value of the two resistors. Therefore, the equivalent resistance value of the light receiving element PD having a large resistance value and the resistance value smaller than the resistance value can be approximated to a low resistance value by connecting the resistors in parallel, without using an expensive measuring device An equivalent resistance can be formed as an area that can be easily measured.

In one embodiment, the resistance value of the resistor 230 connected in parallel with the light receiving element PD can be adjusted according to the substance to be detected and its concentration in the sensing system according to the present embodiment. As another example, the resistance value of the resistor 230 connected in parallel with the light-receiving element PD can be adjusted so that the equivalent resistance value of the light-receiving element PD is included within the measurement range of the measuring instrument for measuring the equivalent resistance value .

4 (a) and 4 (b) are schematic diagrams showing an embodiment of the control unit 300. As shown in FIG. In the embodiment illustrated by FIG. 4 (a), the control unit 300 includes a digital-to-analog converter 310. The digital-to-analog converter 310 receives the digital code from the outside of the sensor and provides the corresponding control voltages Vcon1 and Vcon2 to control the first control power supply 110 and the second control power supply 210 . In the embodiment illustrated by Fig. 4 (b), the control unit 300 further includes a memory 320 for storing codes. The digital-to-analog converter 310 receives the digital code from the memory 320 and provides the control voltages Vcon1 and Vcon2 corresponding to the codes to generate the first control power 110 and the second control power 210, .

In one embodiment, the controller 300 may include a digital-to-analog converter 310 as shown in FIG. The digital-to-analog converter 310 receives a control code from the outside to form corresponding control voltages Vcon1 and Vcon2. The formed control voltages Vcon1 and Vcon2 are provided to the first control power supply 110 and the second control power supply 210. [ Although not shown, the digital-to-analog converter 310 may provide a control voltage to the plurality of

photodetectors

100a, 100b, ..., 100n.

The control unit 300 controls the first control power 110 and the second control power to sweep the value of the bias current provided by the first control power source 110 and the second power source 210 according to an externally provided digital code, And provides the control voltages Vcon1 and Vcon2 provided to the second control power supply 210. [ For example, the control voltage Vcon1 and the control voltage Vcon2 provided by the controller 300 may be controlled by the first control power source 110 and the second control power source 110 so that the bias currents supplied to the light emitting element LED and the light receiving element PD are increased, And is supplied to the second control power supply 210.

For example, when the current supplied from the first control power supply 110 to the light emitting diode (LED) linearly increases and the second control power supply 210 supplies the current to the light receiving element PD The control voltage Vcon1 and the control voltage Vcon2 are provided so as to increase linearly or nonlinearly.

As another example, the control unit 300 determines that the current supplied to the light emitting diode (LED) by the first control power supply 110 increases in a non-linear manner and the current supplied to the light receiving element PD by the second control power supply 210 The control voltage Vcon1 and the control voltage Vcon2 are provided so as to increase linearly or nonlinearly.

The current supplied to the light emitting diode LED by the first control power supply 110 and the current supplied by the second control power supply 210 to the light receiving element PD are increased. May be similarly applied to the case where the current supplied to the light emitting diode (LED) and the current supplied to the light receiving element PD by the second control power supply 210 increase.

2 and 4, the first control power supply 110 and the second control power supply 210 are shown as a controllable current source, but this is only one embodiment, The power source 110 and the second control power source 210 may be a controllable voltage source.

5 is a block diagram showing the outline of the sensor 2 according to the present embodiment. Referring to FIG. 5, the sensor 2 may include a plurality of light providing

units

100a, 100b, ..., 100n. In one embodiment, the plurality of light providing

portions

100a, 100b, ..., 100n may provide different optical stimuli. In one example, the photodetector 100a may provide an ultraviolet stimulus, the photodetector 100b may provide an optical stimulus in the blue band, and the photodetector 100n may provide an optical stimulus in the red band. The medium in which the plurality of light providing

portions

100a, 100b, ..., 100n provide optical stimuli includes one medium including the target, a plurality of mediums including the same target, different concentrations of the same target A plurality of media including one target, a plurality of media comprising different targets, one medium containing different targets, or a plurality of media including different targets.

In another embodiment, the plurality of light providing

portions

100a, 100b, ..., 100n may provide optical stimuli to different media. In one example, the photodetector 100a may provide an optical stimulus to the medium Ma in which the target is contained at the first concentration, and the photodetector 100b may provide an optical stimulus to the medium Mb in which the target is contained at the second concentration And the photodetector 100n may provide an optical stimulus to the medium (Mn) in which the target is contained at the third concentration.

According to another embodiment, which is not shown, the sensor may include one or more light-providing portions and one or more non-optical actuators to provide a stimulus, wherein the sensor is configured to detect stimulation using one or more optical sensing elements and one or more non- Can be detected.

According to yet another embodiment not shown, the sensor may comprise a plurality of detectors. In one example, the sensor may include a plurality of detectors capable of detecting an optical response and a non-optical response, respectively, with respect to the provided stimulus. As another example, the sensor may include a plurality of detectors for detecting the reaction in the infrared light band, the reaction in the visible light band, and the reaction in the ultraviolet light band, respectively, with respect to the provided stimulus.

When the rate of increase of the bias provided by the first control power supply 110 to the actuator act is smaller than the rate of increase of the bias provided by the second control power supply 110 by the detecting element det, . The negative resistance characteristic may not appear as the rate of increase of the bias supplied to the actuator act by the first control power supply 110 gradually increases.

In addition, negative resistance characteristics may or may not appear depending on the characteristics, concentration and optical or non-optical properties of the target contained in the medium. For example, even when the bias is provided to the detecting element det and the actuator act so that the current-voltage characteristic of the detecting element exhibits a negative resistance characteristic, the negative resistance characteristic May not appear. Further, even when the bias is provided to the detecting element det and the actuator act so that the current-voltage characteristic of the detecting element does not exhibit the negative resistance characteristic, negative resistance characteristic is obtained depending on the characteristic, concentration and optical property of the medium .

For example, the optical properties of the target included in the medium may be such as dispersion, absorption, scattering, and phosphorescence.

6 (a) and 6 (b) are diagrams schematically showing a current-voltage curve of a light-receiving element according to an embodiment of the sensor operation. The sensor operation according to this embodiment will be described with reference to Figs. 6 (a) and 6 (b). 6A and 6B, the light receiving element PD is a photodiode, and the light emitting element (LED) is a light emitting diode.

6A, in a state where the bias current provided by the first control power supply 110 to the light emitting element (LED) does not reach the threshold value of the light emitting element (LED) and is turned off, the second control power supply The reverse saturation current of the light receiving element increases as the reverse bias by the bias current provided to the light receiving element PD increases. This corresponds to the current-voltage characteristic of the conventional light receiving element PD.

When the voltage supplied to the light emitting element (LED) is increased by the first control power supply 110 to exceed the threshold voltage which is the light emitting element (LED), the light emitting element (LED) is turned on, Provides optical stimulation. The target is optically reacted by receiving an optical stimulus, and the light-receiving element (PD) detects the optical reaction and provides it in the form of current.

Since the component of the current flowing through the light receiving element PD includes not only the inverse saturation current component but also the current component due to the optical stimulus, the voltage for forming the reverse saturation current decreases, And a voltage difference Vdiff.

Further, when the bias current provided to the light emitting device (LED) gradually increases, the intensity of the optical stimulus provided by the light emitting device increases, so that the current component that the light receiving device detects and outputs the optical reaction must also increase. To compensate for this, the voltage across the photodetector must gradually decrease. Therefore, the voltage Vpd across the light receiving element PD is shifted in the decreasing direction. As a result, after the point S at which the light emitting element LED is turned on, the light receiving element PD exhibits a negative resistance characteristic.

6 (b) is a graph showing the current-voltage curve of the light-receiving element PD when a target according to the present embodiment is detected at different concentrations. 6 (b), the current-voltage relationship is the same as that of the conventional light-receiving element until the turn-on time S of the LED is included in the sensor. However, The light receiving element 210 may generate different current-voltage curves corresponding to the optical response, and may generate different current-voltage curves corresponding to the optical response. do.

Therefore, even if the same current flows in the light receiving element PD according to the concentration of the target included in the medium after the light emitting element LED is turned on, the voltage Vpd at both ends may be different, The concentration of the target can be grasped. As another example, even when the voltage Vpd across the light receiving element PD is the same, the current flowing through the light receiving element PD may be different, and the concentration of the target can be detected by detecting the current. As another example, the concentration of the target can be determined by detecting the current value and the voltage value at which the negative resistance characteristic starts in the light-receiving element PD.

7A is a diagram schematically showing a current-voltage curve of a light-receiving element according to another embodiment of the sensor operation. 7A and 7B, the light receiving element PD is a photodiode, and the light emitting element (LED) is a light emitting diode. A negative resistance region may not be formed when the light emitting element is turned on, such as when a voltage higher than the threshold value of the actuator is supplied during the initial operation.

The current-voltage curve of the light-receiving element PD may have a form as shown in Fig. 7 (a). In this case, the current Ipd flowing in the light receiving element PD is a component of the inverse saturated current component with respect to the voltage Vpd at both ends of the light receiving element PD. In the case of air, it indicates that the light-receiving element detects all of the optical stimuli provided by the light-emitting element without a medium in the absence of a medium. When the light receiving element detects the optical response of the medium containing the target, a current-voltage relationship is formed in the detection range shown by the dotted line between dark and air in Fig. 7 (a) .

Fig. 7 (b) is a diagram illustrating detection of the concentration of a target substance contained in the medium with the sensor according to the present embodiment. Referring to FIG. 7 (b), the optical response may be different depending on the concentration of the medium, and the electrical signals that the light receiving element detects and outputs are different from each other as shown in FIG. 7 (b). In the case of detecting the concentration and / or concentration of the target using the sensor according to the present embodiment, after the same current Itest is provided to the light receiving element as shown in the figure, the voltages Va, Vb, Vc) can be detected and the concentration of the target can be grasped. According to another embodiment not shown, it is possible to provide the same voltage to the light-receiving element, and then detect the current output by the light-receiving element to determine the concentration of the target.

The target can be detected with high sensitivity even by the embodiment illustrated by Figs. 7 (a) and 7 (b). For example, when the optical reaction is detected while the bias provided to the detecting element is fixed, the current-voltage line indicated by dark by the current detected by the optical reaction is merely a parallel movement. However, according to this embodiment, since the bias provided to the detecting element changes and the slope of the current-voltage changes within the detection range, the output sensitively changes even in a small optical response. Therefore, the present embodiment provides an advantage that the target can be detected with high sensitivity.

That is, when the conventional sensor does not show a negative resistance, it forms a current-voltage relationship having a slope similar to that of the dark state in the dark state, and as the light is provided to the detecting element, Moves in parallel along the entire compression and / or current axis while maintaining the slope. Therefore, the change of the current-voltage coordinate pair value formed by providing the light is not large.

However, according to this embodiment, since the bias provided to the detecting element and the actuator changes, the slope of the current-voltage relationship changes in the region shown by the detection range in Fig. 7 (a). Even in the case of a medium containing the same concentration of the target, since the electrical reaction is largely formed in the detecting element, the target can be detected more sensitively and the target detection limit can be extended.

실험예Experimental Example

Hereinafter, an experimental example of the sensor according to the present embodiment will be described with reference to the accompanying drawings. FIG. 8 is a graph showing the result of measuring the optical response through the sensor according to the present embodiment. In FIG. 8, the dark state, the DIW, and the Deionized Water, in which the light emitting element is not turned on, And 10 nM of BSA (Bovine Serum Albumin).

Referring to FIG. 8, in the dark state, the light emitting device (LED) is not turned on. Therefore, it can be confirmed that no optical reaction is detected in the light receiving element PD, and no negative resistance characteristic appears. (The saturation of Vpd at 4000mV is due to the input dynamic range of the digital-to-analog converter used in this experiment.)

However, in the state in which the light emitting device was in operation, a negative resistance region appeared after the point when Vpd of about 600 mV was provided both in the case of measuring the deionized water and the case of measuring 10 nM of BSA in the target. When the same voltage was applied to the light receiving element as an input, when the measurement was performed with 10 nM BSA as a target, a lower current was outputted than when deionized water was measured.

Figure 9 is a plot showing the optical response to 1 nM BSA and the ratio of optical response to deionized water. Referring to FIG. 9, the ratio of the optical response to deionized water and the optical response to 1 nM of BSA detected through the present example was approximately 0.9980. Therefore, according to the sensor of this embodiment, deionized water and 1 nM concentration BSA could be sufficiently discriminated.

The sensor according to the present embodiment can detect a target having a concentration of 1 nM and has a lower detection limit compared to the lowest detection limit of 100 nM to 50 nM of conventional sensors.

10 is a diagram showing a result of detection of a target as an embodiment of a sensor in which a negative resistance region is not formed. In Fig. 10, dark shows the current-voltage relationship of the light-receiving element when the light-receiving element fails to detect an optical reaction at all (the saturation at Vpd of 4000 mV corresponds to the input dynamic range of the digital- ). In the case of air, the light-receiving element detects all the optical stimuli provided by the light-emitting element without a medium.

test is the current-voltage relationship when detecting a phenol concentration of 100 mu M with the sensor according to this embodiment. When detecting a target in the detection region, the current-voltage relationship of the light-receiving element is approximately linear, and the concentration of the target can be detected through the current-voltage relationship.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It will be appreciated that other embodiments are possible. Accordingly, the true scope of the present invention should be determined by the appended claims.

Described above.

Claims

Sensor, said sensor comprising:

An actuator for providing a stimulus, and a first controllable power source for providing driving power to the actuator;

A detecting element including a detecting element for detecting a response to the stimulation and outputting it as an electric signal, and a second controllable power source for providing driving power to the detecting element;

And a control unit for controlling the driving power provided by the first control power source and the second control power source in accordance with a digital code.
The method according to claim 1,

Wherein the actuator is an optical actuator that provides an optical stimulus.
3. The method of claim 2,

Wherein the optical stimulus is at least one selected from the group consisting of infrared, visible, ultraviolet, and laser.
The method according to claim 1,

Wherein the actuator is a non-optical actuator that provides a non-optical stimulus.
3. The method of claim 2,

Wherein the non-optical stimulus is any one or more selected from the group consisting of sound waves, ultrasonic waves, radio frequency (RF), radiation, magnetic fields and electric fields.
The method according to claim 1,

The reaction to the stimulus is an optical reaction,

Wherein the detecting element is an optical detecting element for detecting the optical reaction.
The method according to claim 6,

The optical detecting element includes:

A photodiode, a phototransistor, and a PMT (PhotoMultiplier Tube).
The method according to claim 6,

Wherein the optical response comprises any one of light emission, absorption, scattering and fluorescence.
The method according to claim 1,

The reaction to the stimulus is a non-optical reaction,

Wherein the detecting element is a non-optical detecting element for detecting the non-optical reaction.
The method according to claim 1,

The stimulus is provided to a target to be detected,

Wherein the response is a response of the target to the stimulus.
The method according to claim 1,

The first control power supply providing a bias current to the actuator,

The second control power supply providing a bias current to the sensing element,

Wherein the control unit controls the bias current provided by the first control power supply and the bias current provided by the second control power supply.
The method according to claim 1,

Wherein the controller comprises a digital-to-analog converter for forming an electrical signal corresponding to the code.
13. The method of claim 12,

Wherein the controller further comprises a memory for storing the code.
The method according to claim 1,

Wherein the sensor comprises a plurality of stimulus providing portions.
The method according to claim 1,

Wherein the sensor comprises a plurality of detectors.
The method according to claim 1,

The sensor includes:

And a current and a voltage of the detecting element to detect a target.
The method according to claim 1,

The sensor

And when the detection element has a negative resistance characteristic, detects at least one selected from the group consisting of a current and a voltage of the detection element to detect the target.
The method according to claim 1,

The sensor

And a sensor for detecting at least one selected from a current and a voltage output by the detecting element when the detecting element does not have a negative resistance characteristic.
The method according to claim 1,

The sensor

When the detecting element does not have a negative resistance characteristic, the current and voltage pairs output by the detecting element form a slope-based line,

Wherein the gradient varies depending on the concentration and presence or absence of the target.
The method according to claim 1,

Wherein the sensor is capable of controlling the actuator to control the driving power provided to the detecting element so that the electrical signal output from the detecting element has a negative resistance characteristic or a positive resistance characteristic.