A sensor module for material identification, a method and computer program

Abstract

A sensor module for material identification is provided in accordance with embodiments of the disclosure, the sensor module comprising: at least one triboelectric sensor made of a triboelectric material; and a sensor reset unit, the sensor reset unit being configured to perform a sensor reset process to reset a state of the at least one triboelectric sensor to an initial state; a measurement unit, the measurement unit being configured to acquire data from the triboelectric sensor corresponding to a first measurement once the sensor reset process has been performed. A corresponding method and computer program are also provided in accordance with embodiments of the disclosure.

Description

[0001] A SENSOR MODULE FOR MATERIAL IDENTIFICATION, A METHOD AND COMPUTER PROGRAM

[0002] BACKGROUND

[0003] Field of the Disclosure:

[0004] The present invention relates to a sensor module for material identification, a method and computer program.

[0005] Description of the Related Art:

[0006] The "background" description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in the background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.

[0007] Due to the global issues in waste management, it is crucially important to improve established methods of separating / sorting waste as well as to develop new methods for this purpose. As a means to reduce the amount of wasted materials, recycling of materials plays an important role. Accordingly, methods of sorting materials for sustainable reuse and recycling are required.

[0008] Furthermore, as well as global issues in waste management, methods of validating materials for quality assurance or quality control purposes are also required.

[0009] There are already some established methods (and technologies) for separating mixed plastic, including identifying density differences or through selective dissolution of one component of the mixture to sort, for example. However, these methods themselves are not sustainable since they consume lots of resources (such as power, solvents, and the like) and they are limited to certain specific materials. Some additional methods of sorting, such as measuring the infra-red spectrum, are time consuming and expensive. Other additional methods, such as magnetic sorting methods, are not specific, such that only certain types of materials (such as magnetic versus non-magnetic materials) can be distinguished from each other.

[0010] Use of a self-power sensing element comprising a triboelectric nanogenerator (TENG) has been proposed for use in material identification and / or distinguishing between different materials or different material surfaces, such as described in EP22166160.6 (Sustainable Sorting Device and Method Using Self-Powered TENG). This provides a sustainable and complementary technique to the aforementioned established methods (and technologies) with broader versatility in terms of materials ranging from organic (e.g. plastics) to inorganic (e.g. silicon dioxide) materials.

[0011] However, there is a problem of hysteresis and low reproducibility when using such a sensing element. As such, there is a desire to further improve accuracy and efficiency with which materials can be separated / sorted.

[0012] It is an aim of the present disclosure to address these issues.

[0013] SUMMARY:

[0014] A brief summary about the present disclosure is provided hereinafter to provide basic understanding related to certain aspects of the present disclosure. Embodiments of the present disclosure are defined by the appended claims. Further aspects of the present disclosure are defined by the dependent claims.

[0015] In accordance with embodiments of the disclosure, improved identification of materials can be achieved. In particular, embodiments of the disclosure reduce or eliminate charges from the sensor module between measurements, reducing hysteresis and improving reproducibility. This in turn improves the accuracy and efficiency with which materials can be separated / sorted.

[0016] The present disclosure is not particularly limited to these advantageous technical effects. Further technical effects will become apparent to the skilled person when reading the disclosure.

[0017] BRIEF DESCRIPTION OF THE DRAWINGS:

[0018] Figure 1 illustrates an example apparatus in accordance with embodiments of the disclosure;

[0019] Figure 2 illustrates a sensor module for material identification according to embodiments of the disclosure;

[0020] Figure 3 illustrates a sensor array of a sensor module according to embodiments of the disclosure;

[0021] Figure 4 illustrates an example sensor reset process in accordance with embodiments of the disclosure;

[0022] Figure 5 illustrates an example sensor reset process in accordance with embodiments of the disclosure;

[0023] Figure 6 illustrates an example sensor reset process in accordance with embodiments of the disclosure;

[0024] Figure 7 illustrates an example method of controlling a sensor module in accordance with embodiments of the disclosure.

[0025] DESCRIPTION OF THE EMBODIMENTS:

[0026] The foregoing paragraphs have been provided by way of general introduction, and are not intended to limit the scope of the following claims. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings (wherein like reference numerals designate identical or corresponding parts throughout the several views).

[0027] Referring to Figure 1, an apparatus 1000 according to embodiments of the disclosure is shown. Typically, an apparatus 1000 according to embodiments of the disclosure is a computer device such as a personal computer or a terminal connected to a server. Indeed, in embodiments, the apparatus may also be a server. The apparatus 1000 is controlled using a microprocessor or other processing circuitry 1002. In some examples, the apparatus 1000 may be a portable computing device such as a mobile phone, laptop computer or tablet computing device.

[0028] The processing circuitry 1002 may be a microprocessor carrying out computer instructions or may be an Application Specific Integrated Circuit. The computer instructions are stored on storage medium 1004 which may be a magnetically readable medium, optically readable medium or solid-state type circuitry. The storage medium 1004 may be integrated into the apparatus 1000 or may be separate to the apparatus 1000 and connected thereto using either a wired or wireless connection. The computer instructions may be embodied as computer software that contains computer readable code which, when loaded onto the processor circuitry 1002, configures the processor circuitry 1002 to perform a method according to embodiments of the disclosure.

[0029] Additionally, an optional user input device 1006 is shown connected to the processing circuitry 1002. The user input device 1006 may be a touch screen or may be a mouse or stylist type input device. The user input device 1006 may also be a keyboard or any combination of these devices.

[0030] A network connection 1008 may optionally be coupled to the processor circuitry 1002. The network connection 1008 may be a connection to a Local Area Network or a Wide Area Network such as the Internet or a Virtual Private Network or the like. The network connection 1008 may be connected to a server allowing the processor circuitry 1002 to communicate with another apparatus in order to obtain or provide relevant data. The network connection 1002 may be behind a firewall or some other form of network security.

[0031] Additionally, shown coupled to the processing circuitry 1002, is a display device 1010. The display device 1010, although shown integrated into the apparatus 1000, may additionally be separate to the apparatus 1000 and may be a monitor or some kind of device allowing the user to visualise the operation of the system. In addition, the display device 1010 may be a printer, projector or some other device allowing relevant information generated by the apparatus 1000 to be viewed by the user or by a third party.

[0032] As explained in the Background, due to the global issues in waste management, it is crucially important to improve established methods of separating / sorting waste as well as to develop new methods for this purpose. As a means to reduce the amount of wasted materials, recycling of materials plays an important role. Accordingly, methods of sorting materials for sustainable reuse and recycling are required.

[0033] There are already some established methods (and technologies) for separating mixed plastic, including identifying density differences or through selective dissolution of one component of the mixture to sort, for example. However, these methods themselves are not sustainable since they consume lots of resources (such as power, solvents and the like) and they are limited to certain specific materials. Some additional methods of sorting, such as measuring the infra-red spectrum, are time consuming and expensive. Other additional methods, such as magnetic sorting methods, are not specific, such that only certain types of materials (such as magnetic versus non-magnetic materials) can be distinguished from each other.

[0034] Use of a self-power sensing element comprising a triboelectric nanogenerator (TENG) has been proposed for use in material identification and / or distinguishing between different materials or different material surfaces, such as described in EP22166160.6 (Sustainable Sorting Device and Method Using Self-Powered TENG). This provides a sustainable and complementary technique to the aforementioned established methods (and technologies) with broader versatility in terms of materials ranging from organic (e.g. plastics) to inorganic (e.g. silicon dioxide) materials.

[0035] However, there is a problem of hysteresis and low reproducibility when using such a sensing element. In particular, existing or residual charges on the surface of the sensor pixel(s) can cause increased levels of hysteresis and reduce reproducibility.

[0036] As such, there is a desire to further improve accuracy and efficiency with which materials can be separated / sorted.

[0037] Accordingly, in accordance with embodiments of the disclosure, a sensor module for material identification, a method and a computer program are provided. <Sensor Module>

[0038] Consider, now, Figure 2 of the present disclosure. Figure 2 illustrates a sensor module for material identification according to embodiments of the disclosure.

[0039] The sensor module 2000 illustrated in Figure 2 comprises at least one triboelectric sensor 2002, a sensor reset unit 2002 and a measurement unit 2004.

[0040] The at least one triboelectric sensor 2002 is made of a triboelectric material. In examples, there may be a single triboelectric sensor 2002. In examples, there may be an array of triboelectric sensors, each triboelectric sensor forming a pixel of the sensor module. In examples, each of the at least one triboelectric sensor may be formed of a different triboelectric material.

[0041] When a material comes into contact with the at least one triboelectric sensor 2002, it generates a unique triboelectric signal which can be used for identification of the material.

[0042] The at least one triboelectric sensor 2002 of the sensor module 2000 does not require an external power source. That is, the at least one triboelectric sensor 2002 is self-powering. Accordingly, the efficiency of the senor module is improved (since external power does not need to be supplied to the at least one triboelectric sensor 2002).

[0043] The sensor reset unit 2004 is configured to perform a sensor reset process to reset a state of the at least one triboelectric sensor to an initial state. Details of the sensor reset process performed by the sensor reset unit will be described in more detail later. However, it will be appreciated that the initial state is a state to which the sensor can be returned to reduce hysteresis and improve reproducibility of a measurement performed with the sensor. In examples, the initial state may include a state where charges on the at least one triboelectric sensor are equalised and / or reset, for example.

[0044] In examples, the sensor reset unit 2004 may be configured to perform a sensor reset process for each triboelectric sensor of the at least one triboelectric sensor at the same time. That is, a global reset may be performed. In examples, a sensor reset process may be performed by the sensor reset unit 2004 on an individual basis for each of the at least one triboelectric sensors.

[0045] Consider, now, Figure 3 of the present disclosure. Figure 3 of the present disclosure illustrates a sensor array of a sensor module according to embodiments of the disclosure.

[0046] In this example, the sensor array comprises a plurality of triboelectric sensors. That is, the sensor array illustrated in Figure 3 is an example for a sensing module comprising a plurality of triboelectric sensors and where each of those triboelectric sensors is arranged as part of an array. Indeed, in this example, an array of 5 triboelectric sensors in the horizontal direction and 4 triboelectric sensors in the vertical direction is shown. However, it will be appreciated that the present disclosure is not particularly limited to this example arrangement. The number of triboelectric sensors forming part of the array may be much larger or much smaller than that shown in Figure 3. Indeed, in some examples, there may be a single triboelectric sensor as part of the sensor module.

[0047] Each triboelectric sensor of the sensor array forms a "pixel" of the sensor module. That is, each triboelectric sensor can be used to acquire data which can be used for material identification.

[0048] As noted, in examples, the sensor rest unit 2004 may be configured to perform a global reset of the triboelectric sensors. In the example of Figure 3, this would mean that all of the triboelectric sensors of the sensor array were reset at the same time by the sensor reset unit. For example, the charges on all triboelectric sensors of the sensor array may be reset simultaneously, such that the different pixels of the triboelectric sensors start to accumulate charges at the same time. However, in examples, the sensor reset unit may be configured to perform a sensor reset process for individual triboelectric sensors. For example, a sensor reset process may be performed on the individual pixels once that pixel has undergone an interaction with a sample (i.e. once a material to be measured or identified has come into contact with the pixel of the sensor array). For example, the sensor reset process may be performed for an individual triboelectric sensor 3004 of the sensor array. Alternatively, in examples, the sensor reset process may be performed by the sensor reset unit for a subset of the pixels of the sensor array. As an example, the sensor reset process may be performed for a subset of the triboelectric sensors 3002 of the sensor array.

[0049] Furthermore, in examples, the sensor reset process may be performed by the sensor reset unit 2004 in a sequence for all pixels of the sensor array. For example, the sensor reset process may start at a first triboelectric sensor of the sensor array (say, the top left-hand triboelectric sensor of the sensor array) and then may proceed, in sequence, for all subsequent triboelectric sensors of that row. Then, when all triboelectric sensors in that row have been reset, the sequence may proceed to the first triboelectric sensor on the next row of the sensor array. This sequence may then continue until the final triboelectric sensor (say, the bottom right-hand triboelectric sensor of the sensor array) is reset.

[0050] Therefore, the sensor reset unit 2004 may be configured to perform a different type of sensor reset process depending on the situation to which the embodiments of the disclosure are applied (including, for example, the number of triboelectric sensors present in the sensor module, the type of material identification to be performed and / or the type of sensor reset process to be performed). This improves the flexibility of the reset process and ensures that an appropriate reset process can be performed for the sensor module.

[0051] Returning to Figure 2, it is noted that the measurement unit 2006 is configured to acquire data from the triboelectric sensor corresponding to a first measurement once the sensor reset process has been performed. In examples, the first measurement may correspond to an interaction of a material with the at least one triboelectric sensor. For example, the first measurement may be made after the sensor reset process once a material interacts with the at least one triboelectric sensor. In examples, an interaction may include the material coming into contact with the at least one triboelectric sensor. In examples, the data acquired from the triboelectric sensor may be used as part of a material identification process.

[0052] In the example of Figure 2, the sensor reset unit 2004 and the measurement unit 2006 have been described as separate units within the sensor module. However, it will be appreciated that the present disclosure is not particularly limited in this respect. In examples, the sensor reset unit 2004 and the measurement unit 2006 may be implemented as circuitry within the sensor module. The circuitry may be a microprocessor carrying out instructions or may be an Application Specific Integrated Circuit. The computer instructions may be stored on a storage medium which may be a magnetically readable medium, optically readable medium or solid-state type circuitry, for example.

[0053] In examples, the sensor module may also include one or more further units in addition to those illustrated in Figure 2. For example, the sensor module may include a storage unit configured to store the data acquired by the measurement unit. In examples, the storage unit may be a temporary storage (or buffer) which stores the data acquired by the measurement unit until it is required. In examples, the sensor module may be communicatively coupled with an external storage unit which is configured to store the data acquired by the measurement unit. In examples, the sensor module may also include a processing unit configured to process the data acquired from the measurement unit (e.g. to perform material identification based on the data which has been acquired). However, in examples, the processing to perform material identification may be performed by an external processing unit (e.g. located in a server). The present disclosure is not particularly limited in this respect.

[0054] The sensor module of Figure 2 of the present disclosure has been described with reference to an example whereby the sensor module makes a first measurement (to acquire data from the triboelectric sensor) once the sensor reset has been performed. As has been described, the data which is acquired during the first measurement is data which can be used for material identification, for example. However, in examples, it may be desired that the sensor module makes one or more additional measurements after the first measurement has been made. In examples, this may be because a further sample (material to be identified) has been brought into contact with the triboelectric sensor. Alternatively, this may be because repeated measurements are desired for the first sample (as this may further improve the accuracy of material identification). Accordingly, in examples, a further sensor reset process may be performed once the first measurement has been made.

[0055] That is, in examples, the sensor reset unit 2004 may be configured to perform a second (or further) sensor reset process once the data corresponding to the first measurement has been acquired, the second sensor reset process being performed to reset a state of the at least one triboelectric sensor to the initial state; and the measurement unit 2006 may then be configured to acquire data from the triboelectric sensor corresponding to a second measurement once the second sensor reset process has been performed.

[0056] In examples, a further reset process may be performed by the sensor reset unit 2004 for each measurement which is made by the measurement unit 2006, thus ensuring that for each measurement, the at least one triboelectric sensor is in its initial state (which thus ensures consistency across measurements and improves reproducibility of the measurement). In examples, such as when there are a plurality of triboelectric sensors present on the sensor module, the sensor reset process for the different triboelectric sensors may be performed asynchronously by the sensor reset unit 2004; that is, different triboelectric sensors may be reset at a different time and may have undergone a different number of resets. Alternatively, in examples - such as when a global reset is performed - the triboelectric sensors may be reset synchronously by the sensor reset unit 2004.

[0057] Furthermore, in examples, the timing of the sensor reset which is performed by the sensor reset unit 2004 may also be controlled by the sensor module. That is, in examples, a timing at which the sensor reset unit is configured to perform the sensor reset process may be controlled by a timing signal (e.g. a signal from an external device, indicating that a reset should be performed [such as a signal produced on a periodic basis]), a timing unit (such as an internal clock or other timing unit, which indicates a time at which a sensor reset should be performed), or a timing event (e.g. an interaction with a sample [material to be measured] or completion of a measurement by the measurement unit). Alternatively, in examples, the sensor reset unit may be configured to continually perform the sensor reset process (e.g. such as when the sensor reset process is performed by ionized gas, as is described in more detail later).

[0058] It will be appreciated that with a sensor module according to embodiments of the disclosure (such as that illustrated with reference to Figure 2 of the present disclosure), improved identification of materials can be achieved. In particular, embodiments of the disclosure reduce or eliminate charges from the sensor module between (or before) measurements, reducing hysteresis and improving reproducibility. In addition to these example technical effects, it will be appreciated that performing the reset process in accordance with embodiments of the disclosure reduces sensor drift, since accumulated charges on the sensor are equalised or reset as the sensor is returned to its initial state. Moreover, the influence of humidity and other environmental conditions on the measurement performed using the sensor module are also reduced.

[0059] Therefore, in view of these technical effects as provided by embodiments of the disclosure improved accuracy and efficiency with which materials can be separated / sorted when using a triboelectric sensing device can be achieved.

[0060] Further details of example sensor reset processes of the present disclosure will now be described.

[0061] <Example Reset Processes>

[0062] As explained with reference to Figure 2 of the present disclosure, a sensor module of the present disclosure comprises a sensor reset unit, the sensor reset unit being configured to perform a sensor reset process to reset a state of the at least one triboelectric sensor to an initial state.

[0063] The type of sensor reset process is not particularly limited in accordance with embodiments of the disclosure. Indeed, the sensor reset process may vary depending on the situation to which the embodiments of the disclosure are applied. However, a number of different example implementations of the sensor reset process which may be used in accordance with embodiments of the disclosure will now be described.

[0064] As a first example implementation, it will be appreciated that an ionized gas may be used to perform a sensor reset process in accordance with embodiments of the disclosure. That is, the sensor reset unit 2004 may be configured to use an ionized gas to reset charges on the at least one triboelectric sensor and thus return the at least one triboelectric sensor to its initial state.

[0065] The ionized gas is a gas (or gas mixture) which is not natural, but rather carries an electrical charge. The electrical charge carried by the ionized gas can be used to return the triboelectric sensor to an initial state, if the ionized gas is brought into contact with the triboelectric sensor. For example, the sensor module may be arranged in a certain configuration to perform sensing (e.g. in a location where it can be brought into contact with a sample to be measured). Then, when the sensor reset process is to be performed, the ionized gas can be generated and brought into contact with the triboelectric sensor of the sensor module. As an example, the ionized gas may be blown across the surface of the triboelectric sensor.

[0066] In examples, ionized gas may be used as a sensor reset process which is particularly suited to performing a global reset. That is, in examples, the ionized gas, once generated, may be brought into contact with any number of triboelectric sensors on the sensing module at the same time (e.g. by surrounding the sensor module with the ionized gas, such that the ionized gas comes into contact with the surface of all the triboelectric sensors). However, while the ionized gas can be used in order to perform a global reset, it can also be used in order to perform a targeted (or individual) reset of the sensors. For example, the ionized gas, once created, can be specifically targeted to one or more of the triboelectric sensors of the sensor module in order to reset those specific sensors.

[0067] Furthermore, sensor reset unit 2004 may perform a sensor reset process to reset a state of the at least one triboelectric sensor to an initial state using the ionized gas at a specific instant of time (e.g. immediately prior to a measurement). Alternatively, the sensor reset unit 2004 may use the ionized gas to perform a continuous reset of the sensor module. That is, the ionized gas may be continually generated and brought into contact with the sensor module, such that once an interaction between a sample to be measured and the at least one triboelectric sensor has occurred (and the measurement of the charge generated by that interaction has been made by the measurement unit 2006) the triboelectric sensor will then immediately be brought back to its initial state by the ionized gas (i.e. once the interaction has ended [that is, when the sample is no longer in contact with the triboelectric sensor]).

[0068] In examples, the initial state itself may be controlled by the charge which is applied to the ionized gas (or gas mixture). That is, by changing the charge which is carried by the ionized gas, it is possible to change the state to the triboelectric sensor is returned when it comes into contact with the ionized gas. This enables efficient control of the reset process to be performed by the sensor reset unit.

[0069] Hence, embodiments of the disclosure provide a sensor module, wherein the sensor reset process comprises generating fully or partially ionized gas or gas mixture on a detecting surface side of the at least one triboelectric sensor to reset a state of the at least one triboelectric sensor to the initial state.

[0070] The manner by which the sensor reset unit 2004 is configured to generate the ionized gas (or gas mixture) which can be used to reset the triboelectric sensor is not particularly limited in accordance with embodiments of the disclosure.

[0071] However, in some examples, the ionized gas (or gas mixture) may be generated by a corona discharge. That is, a corona discharge can be used in order to generate ionized gas which can be used in order to reset the triboelectric sensors in accordance with embodiments of the disclosure.

[0072] In examples, the corona discharge may be generated by creating a potential difference (voltage) between two electrodes, where that potential difference is high enough in order to ionize the gas (or gas mixture). Taking air as an example of a gas, the potential difference required to ionize the air would be a potential difference of approximately 30kV / cm, for example. However, the specific potential difference required between the electrodes depends on factors such as the type of gas or gas mixture, the humidity, the temperature and the like. Therefore, the present disclosure is not particularly limited to any specific potential difference between the electrodes, provided that potential difference is high enough to create the ionized gas by corona discharge.

[0073] In examples, the electrodes may be two electrodes which are external to the sensing module. For example, two external electrodes may be provided which, under the control of the sensor reset unit 2004, generate the ionized gas by corona discharge. However, in some examples, one external electrode may be provided, with the other electrode of the electrode pair being provided by the electrode that is the triboelectric sensor. However, in some examples, the corona discharge to generate the ionized gas may be generated with a single electrode (a so-called single-electrode discharge). In examples, the electrode may be a needle or have a sharp tip. The electrodes may be made of any suitable material. In examples, the electrodes may be formed of a ceramic or metallic material.

[0074] Hence, embodiments of the disclosure provide a sensor module, wherein the sensor reset unit is configured to generate the ionized gas or gas mixture by a corona discharge between a pair of electrodes, wherein the pair of electrodes includes either two external electrodes or one external electrode and one electrode of the at least one triboelectric sensor. It will be appreciated that while ionized gas, or gas mixture, provides one way in which the sensor reset unit 2004 can perform a sensor reset process to reset a state of the at least one triboelectric sensor to an initial state, the present disclosure is not particularly limited in this regard.

[0075] As a second example, a conductive element may be used in order to perform a reset of the triboelectric sensor.

[0076] Consider, now, Figure 4 of the present disclosure. Figure 4 illustrates an example sensor reset process in accordance with embodiments of the disclosure. In particular, in the example of Figure 4, a conductive element is brought into contact with the triboelectric sensor in order to reset the triboelectric sensor to an initial state.

[0077] Specifically, the example of Figure 4 of the present disclosure illustrates a triboelectric sensor 4000 (which is an example of the triboelectric sensor 2002 as described with reference to Figure 2 of the present disclosure). The triboelectric sensor 4000 may be a single triboelectric sensor of the sensor module. Alternatively, the triboelectric sensor 4000 may be part of a larger collection of triboelectric sensors of a sensor module (e.g. part of an array of triboelectric sensors, for example).

[0078] Furthermore, in the example of Figure 4 of the present disclosure, a conductive element 4002 is provided. The conductive element may be formed of any material which is a known conductor of electricity. In examples, the conductive element may be a metal element, a conductive metal oxide element, a conductive fabric element or the like.

[0079] In this example, the conductive element 4002 is a moveable element, which can be controlled by the sensor reset unit 2004 of the sensor module. Accordingly, as part of the sensor reset process, the sensor reset unit 2004 may control the position of the conductive element 4002 in order to bring the conductive element 4002 into contact with the surface of the triboelectric sensor 4000.

[0080] In this example of Figure 4, the sensor reset unit 2004 can control the position of the conductive element 4002 in order to press the conductive element on the surface (e.g. top side) of the triboelectric sensor 4000. Once contact has been made, the sensor reset unit 2004 may then control the position of the conductive element 4002 such that it is no longer in contact with the triboelectric sensor (e.g. by retracing its movement, for example). Bringing the conductive element 4002 into contact with the triboelectric sensor 4000 in this manner resets the triboelectric sensor 4000 to its initial state (as described in more detail below).

[0081] However, while the movement of the conductive element 4002 has been described with reference to Figure 4, it will be appreciated that the present disclosure is not particularly limited in this regard. In examples, the movement may be a relative movement between the conductive element 4002 and the triboelectric sensor 4000. Indeed, in examples, this relative movement may be achieved by movement of the triboelectric sensor 4000 to contact the conductive element 4002, for example.

[0082] Furthermore, while the example of Figure 4 of the present disclosure has been described with reference to an example situation whereby the movement is a pressing movement (such that the conductive element 4002 is pressed onto the triboelectric sensor 4000), it will be appreciated that, more generally, any type of movement can be used. For example, the conductor element may be swiped or rolled across the surface of the triboelectric sensor as a type of movement to reset the triboelectric sensor to its initial state.

[0083] In examples, the conductive element 4002 may be grounded, floating, or at a potential relative to the triboelectric sensor 4000. In examples, there may be a potential difference between the triboelectric sensor 4000 and the conductive element 4002. In examples, there may be an alternating potential difference between the triboelectric sensor 4000 and the conductive element 4002. In examples, this potential difference (or alternating potential difference) may be between an electrode of the triboelectric sensor 4000 and the conductive element 4002.

[0084] By bringing the conductive element into contact with the triboelectric sensor, any existing or residual charges on the triboelectric sensor can be reduced or eliminated, thus returning the triboelectric sensor to an initial state (e.g. a state where the charges on the triboelectric sensor are equalised and / or reset).

[0085] The use of a conductive element in order to perform the sensor reset process by the sensor reset unit 2004 enables a targeted (e.g. individual) reset to be performed for the at least one triboelectric sensor of a sensor module very efficiently. For example, the conductive element 4002 may be pressed against one or more specific triboelectric sensors of a triboelectric sensor array in order to reset those specific sensors (e.g. once those sensors have interacted with a sample (a material to be identified) and have thus accumulated charges). Alternatively, a global reset of multiple triboelectric sensors can also be efficiently performed through use of a conductive element 4002. In particular, the conductive element may be shaped such that it can be brought into contact (e.g. pressed, slid, wiped, brushed, rolled, or the like) against the entire surface of a sensor array, such that all individual sensors of that sensor array are reset simultaneously to their initial state. Alternatively, a plurality of conductive elements may be provided, such that each of the plurality of conductive elements comes into contact with one or more of the triboelectric sensors.

[0086] Furthermore, by varying the potential difference between the conductive element and the triboelectric sensor, a different initial state of the triboelectric sensor can be controlled, further improving the flexibility of the reset process performed by the sensor reset unit 2004.

[0087] Hence, embodiments of the disclosure provide a sensor reset process, wherein the sensor reset process comprises controlling a conductive element to bring the conductive element into contact with a detecting surface of the at least one triboelectric sensor to reset a state of the at least one triboelectric sensor to the initial state.

[0088] As a third example of a sensor reset process which can be performed by the sensor reset unit 2004, an insulating element may be used in order to reset the triboelectric sensor to its initial state.

[0089] Consider, now, Figure 5 of the present disclosure. Figure 5 illustrates an example sensor reset process in accordance with embodiments of the disclosure. In particular, in the example of Figure 5, an insulating element is brought into contact with the triboelectric sensor in order to reset the triboelectric sensor to an initial state.

[0090] Specifically, the example of Figure 5 of the present disclosure illustrates a triboelectric sensor 5000 (which is an example of the triboelectric sensor 2002 as described with reference to Figure 2 of the present disclosure). The triboelectric sensor 5000 may be a single triboelectric sensor of the sensor module. Alternatively, the triboelectric sensor 5000 may be part of a larger collection of triboelectric sensors of a sensor module (e.g. part of any array of triboelectric sensors, for example).

[0091] Furthermore, in the example of Figure 5 of the present disclosure, an insulating element 5002 is provided. The insulating element may be formed of any material which is a known insulator of electricity. In examples, the insulating element may be a polymer element, a paper element, a glass element, a ceramic element or an insulating (non-conductive) fabric element, for example.

[0092] In this example, the insulating element 5002 is a moveable element, which can be controlled by the sensor reset unit 2004 of the sensor module. Accordingly, as part of the sensor reset process, the sensor reset unit 2004 may control the position of the insulating element 5002 in order to bring the insulating element 5002 into contact with the surface of the triboelectric sensor 5000.

[0093] In this example of Figure 5, the sensor reset unit 2004 can control the position of the insulating element 5002 in order to cause the insulating element to come into contact with the surface (e.g. top side) of the triboelectric sensor 5000. Indeed, in this example, the insulating element 5002 is brought into contact with the triboelectric sensor 5000 by swiping the insulating element 5002 across the surface of the triboelectric sensor 5000. However, in examples, the sensor reset unit 2004 may perform the sensor reset process by pressing the insulating element 5002 against the surface (as illustrated in Figure 4, with reference to the conductive element 4002). However, it will be appreciated that the present disclosure is not particularly limited in this regard. That is, while the movement of the insulating element 4002 is shown in the example of Figure 5 of the present disclosure, in examples, the sensor reset process may be a relative movement between the insulating element 5002 and the triboelectric sensor 5000. Indeed, in examples, this relative movement may be achieved by movement of the triboelectric sensor 5000 to contact the insulting element 5002, for example. More generally, any type of movement (e.g. pressing, swiping, rolling, brushing, rubbing, or the like) to bring the insulating element 5002 into contact with the triboelectric sensor 5000 can be used.

[0094] Once contact has been made, the sensor reset unit 2004 may then control the position of the insulating element 5002 such that it is no longer in contact with the triboelectric sensor (e.g. by retracing its movement, for example). Bringing the insulating element 5002 into contact with the triboelectric sensor 5000 in this manner resets the triboelectric sensor 5000 to its initial state.

[0095] In examples, a plurality of insulating elements may be used. In examples, of the plurality of different insulating elements may come into contact with one or more triboelectric sensor. In example, the insulating element used as part of the sensor reset process may have a certain (positive or negative) value on the triboelectric scale. By chaining the value of the insulating element, the initial state to which the triboelectric sensor can be returned can be controlled. In example, a plurality of insulating elements may have alternating positive and negative values on the triboelectric scale. By bringing these alternating insulating elements into contact with the triboelectric sensor, the charges on the triboelectric sensor can be efficiently equalised and reset, thus returning the triboelectric sensor to its initial state. In examples, the plurality of insulating elements may have a same (or similar) value on the triboelectric scale.

[0096] The use of an insulating element in order to perform the sensor reset process by the sensor reset unit 2004 enables a targeted (e.g. individual) reset to be performed for the at least one triboelectric sensor of a sensor module very efficiently. For example, the insulating element 5002 may be pressed against one or more specific triboelectric sensors of a triboelectric sensor array in order to reset those specific sensors (e.g. once those sensors have interacted with a sample [a material to be identified] and have thus accumulated charges). Alternatively, a global reset of multiple triboelectric sensors can also be efficiently performed through use of an insulating element 4002. In particular, the insulating element may be shaped such that it can be brought into contact (e.g. pressed) against the entire surface of a sensor array, such that all individual sensors of that sensor array are reset simultaneously to their initial state. Alternatively, a plurality of insulating elements 5002 may be provided, such that each of the insulating elements may make contact with one or more triboelectric sensors.

[0097] As a fourth example, a voltage pulse may be generated, under control of the sensor reset unit 2004, in order to reset a state of the at least one triboelectric sensor to the initial state. That is, in examples, the electrode of the at least one triboelectric sensor may be connected to a device, such as power generating unit, in order to create a potential difference between the at least one triboelectric sensor and the ground. A voltage pulse (e.g. a spike in potential difference, generated for a predetermined period of time) may be generated by the power generating unit in order to create this potential difference between the triboelectric sensor and the ground. The application of this potential difference to the triboelectric sensor (between the triboelectric sensor and the ground) causes the triboelectric sensor to be returned to an initial state (i.e. a state where the charges on the triboelectric sensor are equalised or reset). As previously explained, this improves reproducibility of the sensor measurement and reduces hysteresis in the measurement (since charges from a previous measurement and / or charges which have accumulated on the triboelectric sensor) are reset).

[0098] In examples, the power generating unit may be an AC or a DC power generating unit. That is, the potential difference generated by the power generating unit between the triboelectric sensor and the ground may be an AC or a DC potential difference. The type of power generating unit used in order to generate this potential difference is not particularly limited and may vary depending on the situation to which the embodiments of the disclosure are applied.

[0099] In examples, the power generating unit may be an internal power generating unit (e.g. a power generating unit forming part of the sensor module or a system in which the sensor module is placed). Alternatively, the power generating unit may be an external power generating unit (e.g. a power generating unit which is located outside of the sensor module or a system in which the sensor module is placed). The present disclosure is not particularly limited in this respect.

[0100] The voltage spike generated by the power generating unit under the control of the sensor reset unit 2004 may be used in order to perform a targeted reset of one or more triboelectric sensors. Alternatively, the voltage spike may be used in order to perform a global reset of all of the triboelectric sensors of the sensor module. In examples, the control as to which of the at least one triboelectric sensors of the sensor module are reset by a given voltage spike may be controlled, by the sensor reset unit 2004, by control of the connection between the power generating unit 2004 and the relevant triboelectric sensor(s). Control of this connection may be performed through operation of a switch or the like which connects or disconnects a specific triboelectric sensor from the power generating unit 2004.

[0101] While a number of different examples of a sensor reset process have been described, it will be appreciated that the present disclosure is not particularly limited to any one of these specific examples. Indeed, more generally, the sensor reset unit may be configured to perform any suitable sensor reset process to reset the state of the at least one triboelectric sensor of the sensor module. Indeed, in examples, a combination of the aforementioned sensor reset processes may be applied by the sensor reset unit 2004 in order to reset the state of the at least one triboelectric sensor of the sensor module. That is, each of the specific example sensor reset processes which have been described may be applied either individually or in combination by the sensor reset unit 2004 in order to reset the state of the at least one triboelectric sensor of the sensor module.

[0102] Furthermore, in examples, the sensor reset process performed by the sensor reset unit 2004 may be combined with one or more additional processes to further improve the accuracy and reliability of the measurement.

[0103] Consider, now, Figure 6 of the present disclosure. Figure 6 illustrates an example sensor reset process in accordance with embodiments of the disclosure. In this example, the sensor reset process performed by the sensor reset unit 2004 is combined with an additional process in order to further improve the accuracy and reliability of the measurement. The additional process may include a cleaning process. The cleaning process may be used in order to remove one or more foreign objects or contaminants from the surface of the triboelectric sensor. Indeed, in the specific example of Figure 6 of the present disclosure, the cleaning process comprises the application of a cleaning fluid or substance to the at least one triboelectric sensor prior to performing the sensor reset process.

[0104] That is, in this example, the triboelectric sensor 6000 is being prepared for a measurement (i.e. it is being reset to its initial state before a measurement is performed). Prior to the sensor reset process performed by the sensor unit 2004, a cleaning fluid or substance 6002 is applied to the triboelectric sensor 6000. The cleaning fluid or substance 6002 is used to remove a foreign object or contaminant from the surface of the triboelectric sensor 6000.

[0105] In examples, the cleaning fluid or substance 6002 may be applied by an application unit (not shown). In examples, the application unit may comprise a nozzle or other type of device which can spray the cleaning fluid or substance 6002 across the surface of the triboelectric sensor 6000.

[0106] Once the cleaning fluid or substance 6002 has been applied to the triboelectric sensor 6000, the sensor reset unit 2004 can utilize the sensor reset process in order to remove the cleaning fluid or substance from the surface of the triboelectric sensor 6000.

[0107] In this example, the sensor reset process comprises use of a conductive element 6004. Here, the conductive element is moved across the surface of the triboelectric sensor 6002. As the conductive element is moved across the surface, it removes the cleaning fluid or substance from the surface of the triboelectric sensor. Accordingly, the region behind the conductive element 6004 in the example of Figure 6 (in the direction of movement of the conductive element) is a region for which the cleaning fluid or substance has been removed. The region ahead of the conductive element 6004 (in the direction of movement of the conductive element) is an area to which the cleaning fluid or substance has been applied but has not yet been removed.

[0108] In addition, the use of the conductive element 6004 to remove the cleaning fluid or substance ensures that the triboelectric sensor is reset to an initial state (where the charges on the triboelectric sensor have been equalised or reset) at the same time that the cleaning fluid or substance is removed (through contact of the conductive element 6004 with the surface of the triboelectric sensor). Accordingly, the combination of the reset process performed by the sensor reset unit 2004 with the additional cleaning process in (as demonstrated in this example) means that the cleaning and reset of the triboelectric sensor can be efficiently performed (since an additional element is not required in order to remove the cleaning fluid from the surface of the triboelectric sensor). Moreover, since the triboelectric sensor has been both cleaned and reset, accuracy and reliability of the measurement can be further improved.

[0109] While the example of Figure 6 is described with reference to an example with a single triboelectric sensor, it will be appreciated that the present disclosure is not particularly limited in this regard. In examples, there may be multiple triboelectric sensors present in the sensor module (such as an array of triboelectric sensors). In general, any number of triboelectric sensors can be present in accordance with the present disclosure, provided that the sensor module comprises at least one triboelectric sensor. Furthermore, it will be appreciated that the combined cleaning and sensor reset process of the present disclosure may be applied to in an individual, targeted or global context with respect to the triboelectric sensors of the sensor module. In addition, while describe with reference to a sensor reset process using a conductive element, the cleaning process of the present disclosure may be used in combination with any of the sensor reset processes of the present disclosure (such as the insulating element, for example) or with any combination of the sensor reset processes of the present disclosure (such as the ionized gas and the conductive element, for example).

[0110] <Method>

[0111] Hence, more generally, a method of controlling a sensor module for material identification is provided in accordance with embodiments of the disclosure. An example method of controlling a sensor module is illustrated in Figure 7 of the present disclosure.

[0112] The example method of Figure 7 may be used to control a sensor module such as that described with reference to Figure 2 of the present disclosure, for example. More generally, the example method may be used in order to control a sensor module comprising at least one triboelectric sensor made of a triboelectric material, a sensor reset unit and a measurement unit.

[0113] The example method of Figure 7 starts at step 7000 and proceeds to step 7002.

[0114] In step 7002, the method comprises performing, with the sensor reset unit of the sensor module, a sensor reset process to reset a state of the at least one triboelectric sensor to an initial state.

[0115] Then, in step 7004, the method comprises acquiring, with the measurement unit of the sensor module, data from the triboelectric sensor corresponding to a first measurement once the sensor reset process has been performed.

[0116] The method then proceeds to and ends with step 7006.

[0117] It will be appreciated that the present disclosure is not particularly limited to the steps and arrangement of steps illustrated in Figure 7 of the present disclosure. In particular, a number of these steps may be performed in parallel. Furthermore, a number of additional steps may also be performed in addition to the steps illustrated in Figure 7 as has been described hereinbefore.

[0118] Thus, in accordance with embodiments of the disclosure, improved identification of materials can be achieved. In particular, embodiments of the disclosure reduce or eliminate charges from the sensor module between measurements, reducing hysteresis and improving reproducibility. This in turn improves the accuracy and efficiency with which materials can be separated / sorted.

[0119] <Computer Program>

[0120] Furthermore, it will be appreciated that the methods of the present disclosure may be carried out on conventional hardware (such as that described previously herein) suitably adapted as applicable by software instruction or by the inclusion or substitution of dedicated hardware.

[0121] Thus, the required adaptation to existing parts of a conventional equivalent device may be implemented in the form of a computer program product comprising processor implementable instructions stored on a non-transitory machine-readable medium such as a floppy disk, optical disk, hard disk, PROM, RAM, flash memory or any combination of these or other storage media, or realized in hardware as an ASIC (application specific integrated circuit) or an FPGA (field programmable gate array) or other configurable circuit suitable to use in adapting the conventional equivalent device.

[0122] Separately, such a computer program may be transmitted via data signals on a network such as an Ethernet, a wireless network, the Internet, or any combination of these or other networks. <Clauses>

[0123] In addition, embodiments of the present disclosure can be arranged in accordance with the following numbered clauses:

[0124] 1. A sensor module for material identification, the sensor module comprising: at least one triboelectric sensor made of a triboelectric material; and a sensor reset unit, the sensor reset unit being configured to perform a sensor reset process to reset a state of the at least one triboelectric sensor to an initial state; a measurement unit, the measurement unit being configured to acquire data from the triboelectric sensor corresponding to a first measurement once the sensor reset process has been performed.

[0125] 2. The sensor module according to clause 1, wherein the initial state is a state where charges on the at least one triboelectric sensor are equalised and / or reset.

[0126] 3. The sensor module for material identification according to clause 1 or 2, wherein: the sensor reset unit is further configured to perform a second sensor reset process once the data corresponding to the first measurement has been acquired, the second sensor reset process being performed to reset a state of the at least one triboelectric sensor to the initial state; and the measurement unit is further configured to acquire data from the triboelectric sensor corresponding to a second measurement once the second sensor reset process has been performed.

[0127] 4. The sensor module for material identification according to any preceding clause, wherein the sensor module comprises a plurality of triboelectric sensors and wherein the sensor reset unit is configured to perform a global sensor reset process for the plurality of triboelectric sensors.

[0128] 5. The sensor module for material identification according to any preceding clause, wherein the sensor module comprises a plurality of triboelectric sensors and wherein the sensor reset unit is configured to perform an individual reset process for at least one of the plurality of triboelectric sensors.

[0129] 6. The sensor module for material identification according to any preceding clause, wherein the sensor reset unit is configured to apply a cleaning fluid or substance to the at least one triboelectric sensor prior to performing the sensor reset process.

[0130] 7. The sensor module for material identification according to any preceding clause, wherein the sensor reset process comprises generating fully or partially ionized gas or gas mixture on a detecting surface side of the at least one triboelectric sensor to reset a state of the at least one triboelectric sensor to the initial state.

[0131] 8. The sensor module for material identification according to clause 7, wherein the sensor reset unit is configured to generate the ionized gas or gas mixture by a corona discharge between a pair of electrodes, wherein the pair of electrodes includes either two external electrodes or one external electrode and one electrode of the at least one triboelectric sensor. 9. The sensor module for material identification according to any preceding clause, wherein the sensor reset process comprises controlling a conductive element to bring the conductive element into contact with a detecting surface of the at least one triboelectric sensor to reset a state of the at least one triboelectric sensor to the initial state; and / or wherein the sensor reset process comprises controlling an insulating element to bring the insulating element into contact with a detecting surface of the at least one triboelectric sensor to reset a state of the at least one triboelectric sensor to the initial state.

[0132] 10. The sensor module for material identification according to any preceding clause, wherein a timing at which the sensor reset unit is configured to perform the sensor reset process is controlled by a timing signal, a timing unit, or a timing event; and / or wherein the sensor reset unit is configured to continually perform the sensor reset process.

[0133] 11. The sensor module for material identification according to any preceding clause, wherein the sensor reset process comprises generating a voltage pulse to reset a state of the at least one triboelectric sensor to the initial state.

[0134] 12. The sensor module according to clause 11, whereby the sensor reset unit is configured to generate the voltage pulse by connecting a power generating unit to electrodes of the at least one triboelectric sensor.

[0135] 13. A method of controlling a sensor module for material identification, the sensor module comprising at least one triboelectric sensor made of a triboelectric material, a sensor reset unit and a measurement unit, the method comprising: performing, with the sensor reset unit of the sensor module, a sensor reset process to reset a state of the at least one triboelectric sensor to an initial state; acquiring, with the measurement unit of the sensor module, data from the triboelectric sensor corresponding to a first measurement once the sensor reset process has been performed.

[0136] 14. A computer program comprising instructions which, when executed by a computer, cause the computer to perform a method of controlling a sensor module for material identification, the sensor module comprising at least one triboelectric sensor made of triboelectric material, a sensor reset unit and a measurement unit, the method comprising: performing, with the sensor reset unit of the sensor module, a sensor reset process to reset a state of the at least one triboelectric sensor to an initial state; and acquiring, with the measurement unit of the sensor module, data from the triboelectric sensor corresponding to a first measurement once the sensor reset process has been performed.

[0137] 15. A non-transient computer readable storage medium storing the computer program according to clause 14.

[0138] Obviously, numerous modifications and variations of the present disclosure are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the disclosure may be practiced otherwise than as specifically described herein.

[0139] In so far as embodiments of the disclosure have been described as being implemented, at least in part, by software-controlled data processing apparatus, it will be appreciated that a non-transitory machine-readable medium carrying such software, such as an optical disk, a magnetic disk, semiconductor memory or the like, is also considered to represent an embodiment of the present disclosure.

[0140] It will be appreciated that the above description for clarity has described embodiments with reference to different functional units, circuitry and / or processors. However, it will be apparent that any suitable distribution of functionality between different functional units, circuitry and / or processors may be used without detracting from the embodiments.

[0141] Described embodiments may be implemented in any suitable form including hardware, software, firmware or any combination of these. Described embodiments may optionally be implemented at least partly as computer software running on one or more data processors and / or digital signal processors. The elements and components of any embodiment may be physically, functionally and logically implemented in any suitable way. Indeed, the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. As such, the disclosed embodiments may be implemented in a single unit or may be physically and functionally distributed between different units, circuitry and / or processors.

[0142] Although the present disclosure has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognize that various features of the described embodiments may be combined in any manner suitable to implement the technique.

Claims

CLAIMS:1) A sensor module for material identification, the sensor module comprising: at least one triboelectric sensor made of a triboelectric material; and a sensor reset unit, the sensor reset unit being configured to perform a sensor reset process to reset a state of the at least one triboelectric sensor to an initial state; a measurement unit, the measurement unit being configured to acquire data from the triboelectric sensor corresponding to a first measurement once the sensor reset process has been performed.2) The sensor module according to claim 1, wherein the initial state is a state where charges on the at least one triboelectric sensor are equalised and / or reset.3) The sensor module for material identification according to claim 1, wherein: the sensor reset unit is further configured to perform a second sensor reset process once the data corresponding to the first measurement has been acquired, the second sensor reset process being performed to reset a state of the at least one triboelectric sensor to the initial state; and the measurement unit is further configured to acquire data from the triboelectric sensor corresponding to a second measurement once the second sensor reset process has been performed.4) The sensor module for material identification according to claim 1, wherein the sensor module comprises a plurality of triboelectric sensors and wherein the sensor reset unit is configured to perform a global sensor reset process for the plurality of triboelectric sensors.5) The sensor module for material identification according to claim 1, wherein the sensor module comprises a plurality of triboelectric sensors and wherein the sensor reset unit is configured to perform an individual reset process for at least one of the plurality of triboelectric sensors.6) The sensor module for material identification according to claim 1, wherein the sensor reset unit is configured to apply a cleaning fluid or substance to the at least one triboelectric sensor prior to performing the sensor reset process.7) The sensor module for material identification according to claim 1, wherein the sensor reset process comprises generating fully or partially ionized gas or gas mixture on a detecting surface side of the at least one triboelectric sensor to reset a state of the at least one triboelectric sensor to the initial state.8) The sensor module for material identification according to claim 7, wherein the sensor reset unit is configured to generate the ionized gas or gas mixture by a corona discharge between a pair of electrodes, wherein the pair of electrodes includes either two external electrodes or one external electrode and one electrode of the at least one triboelectric sensor.9) The sensor module for material identification according to claim 1, wherein the sensor reset process comprises controlling a conductive element to bring the conductive element into contact with a detecting surface of the at least one triboelectric sensor to reset a state of the at least one triboelectric sensor to the initial state; and / or wherein the sensor reset process comprises controlling an insulating element to bring the insulating element into contact with a detectingsurface of the at least one triboelectric sensor to reset a state of the at least one triboelectric sensor to the initial state.10) The sensor module for material identification according to claim 1, wherein a timing at which the sensor reset unit is configured to perform the sensor reset process is controlled by a timing signal, a timing unit, or a timing event; and / or wherein the sensor reset unit is configured to continually perform the sensor reset process.11) The sensor module for material identification according to claim 1, wherein the sensor reset process comprises generating a voltage pulse to reset a state of the at least one triboelectric sensor to the initial state.12) The sensor module according to claim 11, whereby the sensor reset unit is configured to generate the voltage pulse by connecting a power generating unit to electrodes of the at least one triboelectric sensor.13) A method of controlling a sensor module for material identification, the sensor module comprising at least one triboelectric sensor made of a triboelectric material, a sensor reset unit and a measurement unit, the method comprising: performing, with the sensor reset unit of the sensor module, a sensor reset process to reset a state of the at least one triboelectric sensor to an initial state; acquiring, with the measurement unit of the sensor module, data from the triboelectric sensor corresponding to a first measurement once the sensor reset process has been performed.14) A computer program comprising instructions which, when executed by a computer, cause the computer to perform a method of controlling a sensor module for material identification, the sensor module comprising at least one triboelectric sensor made of triboelectric material, a sensor reset unit and a measurement unit, the method comprising: performing, with the sensor reset unit of the sensor module, a sensor reset process to reset a state of the at least one triboelectric sensor to an initial state; and acquiring, with the measurement unit of the sensor module, data from the triboelectric sensor corresponding to a first measurement once the sensor reset process has been performed.15) A non-transient computer readable storage medium storing the computer program according to claim 14.

Images