CN114414112A - A flexible pressure sensor and detection method based on passive RFID tag antenna - Google Patents

Abstract

Translated fromChinese

本申请提出一种基于无源RFID标签天线的柔性压力传感器及检测方法。该柔性压力传感器包括：RFID电子标签层、柔性中间层及包含铁氧体的薄膜层，所述RFID电子标签层及包含铁氧体的薄膜层分别配置于柔性中间层的两侧，其中，所述薄膜层位于上侧，RFID电子标签层位于柔性压力传感器的下方侧。该柔性压力传感器利用具有高磁导率和吸波特性的铁氧体，开发了基于RFID的无线传感器装置，使得整个传感器制作成本低、结构简单，并可以通过不同的应用场景来跟换中间的柔性层，具有良好的可替换性。

The present application proposes a flexible pressure sensor and a detection method based on a passive RFID tag antenna. The flexible pressure sensor includes: an RFID electronic label layer, a flexible intermediate layer and a thin film layer containing ferrite, the RFID electronic label layer and the thin film layer containing ferrite are respectively arranged on both sides of the flexible intermediate layer, wherein the The film layer is located on the upper side, and the RFID electronic label layer is located on the lower side of the flexible pressure sensor. The flexible pressure sensor uses ferrite with high magnetic permeability and wave absorption to develop an RFID-based wireless sensor device, which makes the whole sensor low in production cost and simple in structure, and can be replaced by different application scenarios. The flexible layer has good replaceability.

Description

Translated fromChinese

一种基于无源RFID标签天线的柔性压力传感器及检测方法A flexible pressure sensor and detection method based on passive RFID tag antenna

技术领域technical field

本申请涉及传感器技术领域，具体地涉及一种基于无源RFID标签天线的柔性压力传感器及检测方法。The present application relates to the field of sensor technology, in particular to a flexible pressure sensor and a detection method based on a passive RFID tag antenna.

背景技术Background technique

近年来柔性无线传感器由于其出色的机械灵活性和便携性使它在智能设备中被广泛应用。例如智能鞋垫、电子皮肤、智能机器人等。这些先进的智能设备，要求柔性传感器不仅具有柔软舒适特性，还需要实现长距离的无线传输，和轻量化的传感器系统。In recent years, flexible wireless sensors have been widely used in smart devices due to their excellent mechanical flexibility and portability. For example, smart insoles, electronic skins, smart robots, etc. These advanced smart devices require flexible sensors not only to have soft and comfortable properties, but also to achieve long-distance wireless transmission and lightweight sensor systems.

目前，常见的无线传感器采用LC耦合、蓝牙通信以及RFID等技术实现。其中，LC无线传感器是通过外部读取天线和传感器之间的耦合实现，这种无线传感器可以实时检测生理信号且无需外接电源。然而，采用LC天线进行无线传输的最大传输距离仅有1～2厘米，这限制了柔性传感器的实际应用。采用蓝牙通信技术的无线压力传感器具有传输距离远、抗干扰能力强、功耗低，但此类传感器往往需要提供电源供能，这增加了整个传感器系统尺寸和刚性，降低了设备的机械灵活性。一般来说，有源RFID标签支持较远的读取范围，但成本较高。相比之下，无源RFID传感器标签从阅读器接收能量再辐射，成本更低，但是传输的距离较近。At present, common wireless sensors are realized by technologies such as LC coupling, Bluetooth communication, and RFID. Among them, the LC wireless sensor is realized by the coupling between the external reading antenna and the sensor. This wireless sensor can detect physiological signals in real time without external power supply. However, the maximum transmission distance of wireless transmission using LC antennas is only 1-2 cm, which limits the practical application of flexible sensors. Wireless pressure sensors using Bluetooth communication technology have long transmission distance, strong anti-interference ability and low power consumption, but such sensors often need to provide power supply, which increases the size and rigidity of the entire sensor system and reduces the mechanical flexibility of the device . In general, active RFID tags support longer read ranges, but at a higher cost. In contrast, passive RFID sensor tags receive energy from the reader and then radiate it at a lower cost, but the transmission distance is shorter.

因此，需要改进现有的传感器以兼顾成本及传输距离。Therefore, there is a need to improve existing sensors to balance cost and transmission distance.

发明内容SUMMARY OF THE INVENTION

为克服上述存在的缺陷，本申请的目的在于：本申请提出一种基于无源RFID标签天线的柔性压力传感器，实现较远距离的无线压力检测。In order to overcome the above-mentioned defects, the purpose of the present application is as follows: the present application proposes a flexible pressure sensor based on a passive RFID tag antenna, which realizes long-distance wireless pressure detection.

为实现上述目的，本申请采用如下的技术方案：To achieve the above object, the application adopts the following technical solutions:

一种基于无源RFID标签天线的柔性压力传感器，其特征在于，包括：A flexible pressure sensor based on a passive RFID tag antenna, characterized in that it includes:

RFID电子标签层、柔性中间层及包含铁氧体的薄膜层，RFID electronic label layer, flexible intermediate layer and film layer containing ferrite,

所述RFID电子标签层及包含铁氧体的薄膜层分别配置于柔性中间层的两侧，所述薄膜层用以与所述RFID电子标签层耦合，The RFID electronic label layer and the thin film layer containing ferrite are respectively arranged on both sides of the flexible intermediate layer, and the thin film layer is used for coupling with the RFID electronic label layer,

其中，所述薄膜层位于上侧，RFID电子标签层位于柔性压力传感器的下方侧。该RFID电子标签层用于贴附在被测物体上。该柔性压力传感器利用无源RFID标签天线与具有高磁导率的铁氧体之间的互相耦合，并且在一定压力范围内具有高灵敏度和良好的稳定性。该方式下可很好的兼顾成本及传输距离。Wherein, the film layer is located on the upper side, and the RFID electronic label layer is located on the lower side of the flexible pressure sensor. The RFID electronic label layer is used to attach to the object to be measured. The flexible pressure sensor utilizes the mutual coupling between the passive RFID tag antenna and the ferrite with high magnetic permeability, and has high sensitivity and good stability within a certain pressure range. In this way, cost and transmission distance can be well taken into account.

优选的，该RFID电子标签层为偶极子含芯片的超高频无源标签。Preferably, the RFID electronic label layer is a dipole ultra-high frequency passive label containing a chip.

优选的，该RFID电子标签层包括:对称的偶极子天线和RFID芯片，且RFID芯片位于偶极子天线的中间。Preferably, the RFID electronic label layer includes: a symmetrical dipole antenna and an RFID chip, and the RFID chip is located in the middle of the dipole antenna.

优选的，该柔性中间层选自弹性织物、海绵或硅胶中的至少一种。Preferably, the flexible intermediate layer is selected from at least one of elastic fabric, sponge or silica gel.

优选的，该基于无源RFID标签天线的柔性压力传感器，其特征在于，Preferably, the flexible pressure sensor based on passive RFID tag antenna is characterized in that:

还包括粘接剂，其用于连接RFID电子标签层与柔性中间层以及柔性中间层与包含铁氧体的薄膜层。Also included is an adhesive for connecting the RFID electronic label layer and the flexible intermediate layer and the flexible intermediate layer and the ferrite-containing film layer.

优选的，该粘接剂为双面胶或超薄双面胶。Preferably, the adhesive is double-sided tape or ultra-thin double-sided tape.

优选的，该无源RFID电子标签层的远离薄膜层侧还配置有粘接层，通过该粘接层贴附于被测物体。Preferably, the passive RFID electronic label layer is further provided with an adhesive layer on the side away from the film layer, and is attached to the object to be measured through the adhesive layer.

本申请实施例提供一种柔性压力传感器的制作方法，其特征在于，所述制作方法包括：An embodiment of the present application provides a manufacturing method of a flexible pressure sensor, wherein the manufacturing method includes:

基于切割装置将粘接剂、铁氧体薄膜层、柔性中间层切割成预设形状的矩形，在RFID电子标签上依次层叠粘接剂、柔性中间层、双面胶带粘接剂及铁氧体薄膜层，以得到柔性压力传感器。Based on the cutting device, the adhesive, the ferrite film layer and the flexible intermediate layer are cut into rectangles with a preset shape, and the adhesive, flexible intermediate layer, double-sided tape adhesive and ferrite are sequentially laminated on the RFID electronic label thin film layer to obtain a flexible pressure sensor.

本申请实施例提供一种基于无源RFID标签天线的柔性压力传感器的检测方法，其特征在于，The embodiment of the present application provides a detection method for a flexible pressure sensor based on a passive RFID tag antenna, which is characterized in that:

包括上述柔性压力传感器，所述检测方法包括：Including the above-mentioned flexible pressure sensor, the detection method includes:

所述柔性压力传感器接收并响应阅读器发出的电磁波，在RFID电子标签层及薄膜层上分别产生射频电流，标签上感应到的射频电流与薄膜层互耦，The flexible pressure sensor receives and responds to the electromagnetic waves emitted by the reader, and generates radio frequency currents on the RFID electronic label layer and the film layer respectively, and the radio frequency current sensed on the label is coupled with the film layer.

所述柔性压力传感器发生形变时，感应电流被扰动，进而后向散射信号强度发生变化。检测时，RFID电子标签层侧贴附在被测物体上，这样阅读器读取后向散射信号强度来检测压力。采用偶极子含芯片的超高频(UHF)无源标签，实现在5-7米距离上也能读取。When the flexible pressure sensor is deformed, the induced current is disturbed, and then the intensity of the backscattered signal changes. During detection, the RFID electronic label layer side is attached to the object to be tested, so that the reader reads the backscattered signal strength to detect the pressure. The ultra-high frequency (UHF) passive tag with dipole chip is used to realize reading at a distance of 5-7 meters.

有益效果beneficial effect

与现有技术相比，本申请实施方式的基于无源RFID标签天线的柔性压力传感器，利用具有高磁导率和吸波特性的铁氧体使得整个传感器制作成本低、结构简单，该传感器能实现远距离的读取，并可以通过调整中间柔性层的来适应不同的应用场景，具有良好的可替换性。该传感器在法向线方向上的最小可测分辨率为0.12kPa，最大测量压力为10kPa。Compared with the prior art, the flexible pressure sensor based on the passive RFID tag antenna of the embodiment of the present application utilizes ferrite with high magnetic permeability and wave absorption properties to make the whole sensor low in production cost and simple in structure. It can realize long-distance reading, and can adapt to different application scenarios by adjusting the intermediate flexible layer, and has good replaceability. The minimum measurable resolution of the sensor in the normal line direction is 0.12kPa, and the maximum measurement pressure is 10kPa.

附图说明Description of drawings

图1a为本申请实施例的RFID标签天线等效电路图，1a is an equivalent circuit diagram of an RFID tag antenna according to an embodiment of the application,

图1b为本申请实施例的传感器的结构示意图，FIG. 1b is a schematic structural diagram of a sensor according to an embodiment of the application,

图2a为本申请实施例的传感器在垂直负载作用下RSSI值的变化与力的关系，Fig. 2a shows the relationship between the change of RSSI value and the force of the sensor according to the embodiment of the application under the action of vertical load,

图2b为本申请实施例的传感器RSSI值的变化与中间层形变的关系，Fig. 2b shows the relationship between the change of the RSSI value of the sensor and the deformation of the intermediate layer according to the embodiment of the application,

图2c为本申请实施例的传感器的应力与应变的关系，FIG. 2c is the relationship between the stress and the strain of the sensor according to the embodiment of the application,

图3a为本申请实施例的不同传感器在垂直负载作用下RSSI值的变化与力的关系的示意，Fig. 3a is a schematic diagram of the relationship between the change of RSSI value and the force under the action of vertical load of different sensors of the embodiment of the application,

图3b为本申请实施例的不同传感器RSSI值的变化与中间层形变的关系的示意，Fig. 3b is a schematic diagram of the relationship between the variation of the RSSI value of different sensors and the deformation of the intermediate layer according to the embodiment of the application,

图3c为本申请实施例的不同传感器的应力与应变的关系的示意，FIG. 3c is a schematic diagram of the relationship between stress and strain of different sensors according to the embodiment of the application,

图4a为本申请实施例的传感器在法向方向上最小可检测的力的示意，4a is a schematic diagram of the minimum detectable force in the normal direction of the sensor according to the embodiment of the application,

图4b为本申请实施例的传感器在0.033Hz的重复机械负载下的传感器响应示意。FIG. 4b is a schematic diagram of the sensor response of the sensor of the embodiment of the application under repeated mechanical load of 0.033 Hz.

具体实施方式Detailed ways

以下结合具体实施例对上述方案做进一步说明。应理解，这些实施例是用于说明本申请而不限于限制本申请的范围。实施例中采用的实施条件可以如具体厂家的条件做进一步调整，未注明的实施条件通常为常规实验中的条件。The above scheme will be further described below in conjunction with specific embodiments. It should be understood that these examples are intended to illustrate the present application and not to limit the scope of the present application. The implementation conditions used in the examples can be further adjusted such as the conditions of specific manufacturers, and the implementation conditions that are not specified are usually the conditions in routine experiments.

本申请提出一种基于无源RFID标签天线的柔性压力传感器(下称传感器)，This application proposes a flexible pressure sensor (hereinafter referred to as a sensor) based on a passive RFID tag antenna,

该柔性压力传感器包括：无源RFID电子标签层、柔性中间层及包含铁氧体的薄膜层,其依次层叠配置。该柔性压力传感器的薄膜层(也称铁氧体薄膜)位于上侧(顶层)。无源RFID电子标签层位于传感器的下方侧(底层)。该RFID电子标签层侧用于贴附在待测物体上，较佳的，RFID电子标签层为偶极子含芯片的超高频(UHF)无源标签。该RFID电子标签属于远距离的电子标签，读取距离在5-7米，具有较远的检测距离。柔性中间层选自弹性织物、海绵、硅胶等。该方式下，利用具有高磁导率和吸波特性的铁氧体薄膜层使得整个传感器制作成本低、结构简单。The flexible pressure sensor includes: a passive RFID electronic label layer, a flexible intermediate layer and a thin film layer containing ferrite, which are sequentially stacked and configured. The thin film layer (also called ferrite film) of the flexible pressure sensor is located on the upper side (top layer). The passive RFID electronic label layer is located on the lower side (bottom layer) of the sensor. The layer side of the RFID electronic label is used to be attached to the object to be tested. Preferably, the layer of the RFID electronic label is a dipole ultra-high frequency (UHF) passive label with a chip. The RFID electronic tag is a long-distance electronic tag, with a reading distance of 5-7 meters and a long detection distance. The flexible intermediate layer is selected from elastic fabric, sponge, silicone and the like. In this way, the use of the ferrite thin film layer with high magnetic permeability and wave absorption property makes the whole sensor low in fabrication cost and simple in structure.

接下结合附图来描述本申请提出的传感器。Next, the sensor proposed in the present application will be described with reference to the accompanying drawings.

如图1b所示为本申请实施例的RFID标签的结构示意图，Figure 1b is a schematic structural diagram of the RFID tag according to the embodiment of the application,

该标签包括：无源RFID电子标签层30、柔性中间层20及包含铁氧体的薄膜层10。薄膜层10为顶层，使用时无源RFID电子标签层30侧贴附于被测物体上。The label includes: a passive RFIDelectronic label layer 30 , a flexibleintermediate layer 20 and athin film layer 10 containing ferrite. Thefilm layer 10 is the top layer, and the passive RFIDelectronic label layer 30 side is attached to the object to be measured during use.

下面结合图1a来描述本申请实施例的RFID标签，等效电路如图1a所示，The RFID tag of the embodiment of the present application will be described below with reference to Fig. 1a, and the equivalent circuit is shown in Fig. 1a,

标签具有偶极子天线32和内部的RFID芯片31，RFID芯片31位于两偶极子天线32之间。较佳的，两偶极子天线32沿RFID芯片31对称。The tag has adipole antenna 32 and aninternal RFID chip 31 , and theRFID chip 31 is located between the twodipole antennas 32 . Preferably, the twodipole antennas 32 are symmetrical along theRFID chip 31 .

其中，Voc(ω)是在偶极子天线上由入射的角频率射频波所产生的开路电压，Vin(ω)为在芯片端上感应到的电压。Among them, Voc(ω) is the open circuit voltage generated by the incident angular frequency radio frequency wave on the dipole antenna, and Vin(ω) is the voltage induced on the chip end.

从等效电路出发，IC的阻抗Zc遵循以下表达式：Starting from the equivalent circuit, the impedance Zc of the IC follows the following expression:

式中，Rc(ω)为IC的电阻，Cc(ω)为IC的电抗。阅读器发出的电磁波在标签天线及其针对的铁氧体薄膜层上产生射频电流。由于标签天线与铁氧体薄膜层距离较近，在标签上感应到的射频电流与铁氧体薄膜层之间存在很强的互耦。当传感器受压发生形变时，感应电流被扰动，标签天线的阻抗变化，而IC阻抗保持不变。由于阻抗失配，与集成电路耦合的功率和阅读器测量的RSSI(Received Signal Strength Indication)给出的后向散射信号强度在传感器受压时也会发生变化，我们通过检测阅读器的RSSI值来读取传感器所受到的压力。where Rc(ω) is the resistance of the IC and Cc(ω) is the reactance of the IC. Electromagnetic waves emitted by the reader generate radio frequency currents on the tag antenna and the ferrite film layer it targets. Due to the close distance between the tag antenna and the ferrite film layer, there is a strong mutual coupling between the RF current induced on the tag and the ferrite film layer. When the sensor is deformed under pressure, the induced current is disturbed, and the impedance of the tag antenna changes, while the IC impedance remains unchanged. Due to impedance mismatch, the backscattered signal strength given by the power coupled to the integrated circuit and the RSSI (Received Signal Strength Indication) measured by the reader will also change when the sensor is pressurized. We detect the RSSI value of the reader to determine Read the pressure on the sensor.

在一实施方式中，还包括保护膜，该保护膜贴附在无源RFID电子标签层及包含铁氧体的薄膜层上。In one embodiment, a protective film is also included, and the protective film is attached to the passive RFID electronic label layer and the thin film layer containing ferrite.

在一实施方式中，无源RFID电子标签层的远离薄膜层侧还配置有粘接层，通过该粘接层柔性压力传感器贴附于被测物体。In one embodiment, the passive RFID electronic label layer is further provided with an adhesive layer on the side away from the film layer, and the flexible pressure sensor is attached to the object to be measured through the adhesive layer.

本申请实施提供一种该柔性压力传感器的制作方法，制作时包括：The present application provides a manufacturing method of the flexible pressure sensor, which includes:

基于切割装置(如掩模对准曝光机(VersaLaser，30W，Universal Laser))将双面胶、铁氧体薄膜、柔性中间层(如柔性海绵)切割成大小形状相同的矩形，Based on cutting device (such as mask alignment exposure machine (VersaLaser, 30W, Universal Laser)), the double-sided tape, ferrite film, flexible intermediate layer (such as flexible sponge) are cut into rectangles with the same size and shape,

然后在RFID电子标签上依次层叠粘接剂(如双面胶带)、柔性中间层、双面胶带粘接剂(如双面胶带)及铁氧体薄膜，以得到柔性压力传感器的成品。Then, an adhesive (such as double-sided tape), a flexible intermediate layer, a double-sided tape adhesive (such as double-sided tape) and a ferrite film are sequentially laminated on the RFID electronic label to obtain a finished product of the flexible pressure sensor.

在其他的实施方式中，可在一场所预先切割好，然后至另一场所贴装。In other embodiments, it may be pre-cut at one location and then mounted at another location.

上述的基于无源RFID标签天线的柔性压力传感器在检测时，RFID电子标签层侧贴附在被测物体上，When the above-mentioned flexible pressure sensor based on passive RFID tag antenna is detected, the RFID electronic tag layer side is attached to the object to be measured,

检测方法包括：Detection methods include:

柔性压力传感器接收并响应阅读器发出的电磁波，在RFID电子标签层及薄膜层上分别产生射频电流，标签上感应到的射频电流与薄膜层互耦，The flexible pressure sensor receives and responds to the electromagnetic waves emitted by the reader, and generates radio frequency currents on the RFID electronic label layer and the film layer respectively.

柔性压力传感器收到压力后形体发生形变时，标签上感应到的射频电流(有些也称感应电流)被扰动，进而后向散射信号强度发生变化。通过检测阅读器的RSSI值来读取传感器所受到的压力。该柔性压力传感器采用偶极子含芯片的超高频(UHF)无源标签，实现在5-7米距离上也能读取，且实现的成本低。When the flexible pressure sensor deforms after receiving the pressure, the radio frequency current (some also called induced current) induced on the label is disturbed, and then the intensity of the backscattered signal changes. The pressure on the sensor is read by detecting the RSSI value of the reader. The flexible pressure sensor adopts an ultra-high frequency (UHF) passive tag with a dipole chip, which can be read at a distance of 5-7 meters, and the realization cost is low.

接下来结合具体实施方式来验证本申请提出的柔性压力传感器的性能指标。Next, the performance indicators of the flexible pressure sensor proposed in this application are verified with reference to the specific embodiments.

(1)对垂直压力的RSSI(Received Signal Strength Indication)响应(1) RSSI (Received Signal Strength Indication) response to vertical pressure

当传感器受到垂直向下的压力时，中间的柔性层会发生形变，缩短了顶层铁氧体薄膜层与底层的RFID标签之间的距离。当阅读器以恒定的频率(915MHz)向标签天线发射电磁波，由于铁氧体薄膜层和RFID标签间的距离变小，使得铁氧体薄膜层吸收了更多电磁波的能量从而降低了标签的读取率，提高了RSSI的值。通过监测阅读器的RSSI值来读取传感器的所受到的压力。When the sensor is subjected to vertical downward pressure, the flexible layer in the middle deforms, shortening the distance between the top ferrite film layer and the bottom RFID tag. When the reader transmits electromagnetic waves to the tag antenna at a constant frequency (915MHz), since the distance between the ferrite film layer and the RFID tag becomes smaller, the ferrite film layer absorbs more energy of electromagnetic waves and reduces the readability of the tag. The fetch rate increases the value of RSSI. The pressure on the sensor is read by monitoring the RSSI value of the reader.

如图2a所示，在外力负载的作用下传感器的相对RSSI变化。从图中可看出：当负载从0-4.5kPa逐渐增加，传感器的响应(RSSI)值逐渐变小，As shown in Fig. 2a, the relative RSSI of the sensor changes under the external force load. It can be seen from the figure that when the load gradually increases from 0-4.5kPa, the response (RSSI) value of the sensor gradually decreases,

且在0-2.1kPa时的灵敏度为-1.305dbm kPa-1，And the sensitivity at 0-2.1kPa is -1.305dbm kPa-1,

在2.1kPa至4.5kPa时的灵敏度为-4.470dbm kPa-1，可以发现在低压状态和高压状态下传感器具有不同的灵敏度。The sensitivity at 2.1kPa to 4.5kPa is -4.470dbm kPa-1, and it can be found that the sensor has different sensitivities under low pressure state and high pressure state.

从图2b所示，当铁氧体以恒定的位移下降靠近RFID标签时，其相对RSSI变化值与下降位移几乎呈线性关系，而图2c所示，则体现了传感器柔性中间层的应力与应变的关系，可以发现在外加负载从0增加到2.1kPa时，铁氧体下降了1.2mm，而当负载从2.1kPa继续增加达到4.5kPa时，铁氧体下降了3.3mm。根据以上现象可以说明传感器灵敏度曲线分段是因为柔性中间层的应力与应变不线性关系导致。As shown in Figure 2b, when the ferrite drops close to the RFID tag with a constant displacement, its relative RSSI change value is almost linear with the drop displacement, while Figure 2c shows the stress and strain of the flexible intermediate layer of the sensor It can be found that when the applied load increases from 0 to 2.1kPa, the ferrite decreases by 1.2mm, and when the load continues to increase from 2.1kPa to 4.5kPa, the ferrite decreases by 3.3mm. According to the above phenomenon, it can be explained that the segmentation of the sensor sensitivity curve is caused by the nonlinear relationship between the stress and strain of the flexible intermediate layer.

在一实施方式中，采用不同密度的柔性中间层的传感器比较，分别选择了厚度为0.5cm的高密度和低密度的柔性海绵来制作传感器。In one embodiment, the sensors using flexible intermediate layers of different densities are compared, and high-density and low-density flexible sponges with a thickness of 0.5 cm are respectively selected to make the sensors.

如图3a-图3c图所示，由于中间层的柔性海绵密度不同导致传感器的测量范围不同。高密度中间层的传感器最大承受负载为4.5kPa(如图3a),而低密度海绵的最大承受负载为2.91kPa(如图3a图)。此外，我们发现在大于1.3kPa的负载时，低密度海绵构成的传感器的灵敏度具有7.08dbmkPa-1(如图3a图)。As shown in Fig. 3a-Fig. 3c, the measurement range of the sensor is different due to the different density of the flexible sponge in the middle layer. The maximum load of the sensor with the high-density intermediate layer is 4.5kPa (as shown in Figure 3a), while the maximum load of the low-density sponge is 2.91kPa (as shown in Figure 3a). In addition, we found that the sensitivity of the sensor composed of low-density sponges has a sensitivity of 7.08dbmkPa-1 at loads greater than 1.3kPa (Fig. 3a).

(3)检测极限、重复性和环境适应性(3) Detection limit, repeatability and environmental adaptability

我们通过时间分辨实验确定了法向方向上的最小可检测力(如图4a所示)。测得在低压下，法向力为1.81kPa,相对RSSI值变化为1.6dbm。在高压下，法向力从1.97kPa变为2.09kPa时，相对RSSI值变化为1.4dbm。此外，我们还研究了通过在法向方向上施加不同的机械载荷(从0到2.2kPa)来研究机械重复性。对于该范围内所有机械载荷，传感器能够灵敏地响应动态载荷并返回其原始值(如图4b所示)。结果表明，我们的传感器在所施加的力范围内具有出色的可重复性。We determined the minimum detectable force in the normal direction by time-resolved experiments (shown in Fig. 4a). Measured under low pressure, the normal force is 1.81kPa, and the relative RSSI value change is 1.6dbm. Under high pressure, when the normal force changes from 1.97kPa to 2.09kPa, the relative RSSI value changes by 1.4dbm. In addition, we also investigated the mechanical repeatability by applying different mechanical loads (from 0 to 2.2 kPa) in the normal direction. For all mechanical loads in this range, the sensor responds sensitively to dynamic loads and returns to its original value (as shown in Figure 4b). The results show that our sensor has excellent repeatability over the range of applied forces.

上述实施例只为说明本申请的技术构思及特点，其目的在于让熟悉此项技术的人是能够了解本申请的内容并据以实施，并不能以此限制本申请的保护范围。凡如本申请精神实质所做的等效变换或修饰，都应涵盖在本申请的保护范围之内。The above-mentioned embodiments are only intended to illustrate the technical concept and characteristics of the present application, and the purpose thereof is to enable those who are familiar with the technology to understand the contents of the present application and implement them accordingly, and cannot limit the protection scope of the present application. All equivalent transformations or modifications made in accordance with the spirit and spirit of this application shall be covered within the protection scope of this application.

Claims (9)

Translated fromChinese

1.一种基于无源RFID标签天线的柔性压力传感器，其特征在于，包括：1. a flexible pressure sensor based on passive RFID tag antenna, is characterized in that, comprises:RFID电子标签层、柔性中间层及包含铁氧体的薄膜层，RFID electronic label layer, flexible intermediate layer and film layer containing ferrite,所述RFID电子标签层及包含铁氧体的薄膜层分别配置于柔性中间层的两侧，所述薄膜层用以与所述RFID电子标签层耦合，所述RFID电子标签层用于贴附于待测物体。The RFID electronic label layer and the thin film layer containing ferrite are respectively arranged on both sides of the flexible intermediate layer, the thin film layer is used for coupling with the RFID electronic label layer, and the RFID electronic label layer is used for attaching to the RFID electronic label layer. object to be tested.2.如权利要求1所述的基于无源RFID标签天线的柔性压力传感器，其特征在于，2. The flexible pressure sensor based on passive RFID tag antenna as claimed in claim 1, characterized in that,所述RFID电子标签层为偶极子含芯片的超高频无源标签。The RFID electronic label layer is a dipole ultra-high frequency passive label with a chip.3.如权利要求1所述的基于无源RFID标签天线的柔性压力传感器，其特征在于，3. The flexible pressure sensor based on passive RFID tag antenna according to claim 1, wherein,所述RFID电子标签层包括:对称偶极子天线和RFID芯片，且RFID芯片位于偶极子天线的中间。The RFID electronic label layer includes: a symmetrical dipole antenna and an RFID chip, and the RFID chip is located in the middle of the dipole antenna.4.如权利要求1-3中任一项所述的基于无源RFID标签天线的柔性压力传感器，其特征在于，4. The flexible pressure sensor based on passive RFID tag antenna according to any one of claims 1-3, wherein,所述柔性中间层选自弹性织物、海绵或硅胶中的至少一种。The flexible intermediate layer is selected from at least one of elastic fabric, sponge or silica gel.5.如权利要求4中任一项所述的基于无源RFID标签天线的柔性压力传感器，其特征在于，5. The flexible pressure sensor based on passive RFID tag antenna according to any one of claims 4, wherein,所述柔性中间层的厚度介于0.5mm-5mm。The thickness of the flexible intermediate layer is between 0.5mm-5mm.6.如权利要求1所述的基于无源RFID标签天线的柔性压力传感器，其特征在于，6. The flexible pressure sensor based on passive RFID tag antenna according to claim 1, wherein,还包括：粘接剂，其用于连接RFID电子标签层与柔性中间层以及柔性中间层与包含铁氧体的薄膜层。Also included: an adhesive for connecting the RFID electronic label layer and the flexible intermediate layer and the flexible intermediate layer and the ferrite-containing film layer.7.如权利要求6所述的基于无源RFID标签天线的柔性压力传感器，其特征在于，7. The flexible pressure sensor based on passive RFID tag antenna as claimed in claim 6, wherein,所述粘接剂为双面胶或超薄双面胶。The adhesive is double-sided tape or ultra-thin double-sided tape.8.如权利要求1所述的基于无源RFID标签天线的柔性压力传感器，其特征在于，8. The flexible pressure sensor based on passive RFID tag antenna according to claim 1, wherein,所述RFID电子标签层的远离薄膜层侧还配置有粘接层，通过所述粘接层柔性压力传感器于被测物体。An adhesive layer is also arranged on the side of the RFID electronic label layer away from the film layer, and the flexible pressure sensor is connected to the object to be measured through the adhesive layer.9.一种基于无源RFID标签天线的柔性压力传感器的检测方法，其特征在于，9. A detection method for a flexible pressure sensor based on a passive RFID tag antenna, characterized in that,包括如权利要求1-8中任一项所述的柔性压力传感器，所述检测方法包括：Including the flexible pressure sensor according to any one of claims 1-8, the detection method comprises:所述柔性压力传感器接收并响应阅读器发出的电磁波，在RFID电子标签层及薄膜层上分别产生射频电流，标签层上感应到的射频电流与薄膜层互耦，The flexible pressure sensor receives and responds to the electromagnetic waves emitted by the reader, and generates radio frequency currents on the RFID electronic label layer and the film layer respectively, and the radio frequency current sensed on the label layer and the film layer are mutually coupled,所述柔性压力传感器发生形变时，标签层上感应到的射频电流被扰动，进而后向散射信号强度发生变化。When the flexible pressure sensor is deformed, the radio frequency current sensed on the label layer is disturbed, and then the intensity of the backscattered signal changes.

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