Patent Description:
Such sensors are known from <CIT> and <CIT>, wherein the sensors are provided in a dry state and a liquid test sample can be applied to the device and transported to the sensor region within the device by capillary flow. The sensor can include a formation having an array of membranes comprising amphipathic molecules using an array of volumes of polar medium. The sensor can include a lipid bilayer. Other types of sensors are known, such as ion selective sensors comprising an ion selective membrane.

After initial manufacture the sensor is dry, and the component can receive a liquid to form an array of membranes, such as an array of volumes of polar medium which can be used in a range of applications, including the formation of membranes comprising amphipathic molecules.

Another example is provided by <CIT> which represents the closest prior art and discloses an apparatus for creating layers of amphiphilic molecules. The apparatus includes a component configured to engage with a receiver, the component comprising: a substrate comprising plurality of wells; a plurality of well electrodes in respective wells; a common chamber above the wells comprising a common electrode, wherein each well forms part of a sensor for receiving a fluid, wherein a membrane is formable across each well to separate fluid in the well from a fluid in said common chamber; and an array of electrodes configured to connect with a corresponding array of connectors on the receiver by a solder bump, wherein each of the electrodes of the array are electrically connected via a respective via in the substrate to a respective well electrode.

An analysis apparatus incorporating means to provide amphiphilic membranes and nanopores to the sensor is also disclosed by <CIT>.

Known sensors are incorporated within expensive test apparatus that provide high performance analysis of sensor readings across a broad range of tests or applications. These sophisticated devices have sensors that are sensitive and are protected through incorporation and encapsulation, while the data read from the sensors must be read quickly and efficiently.

Although the concept of segregating a function of an apparatus in to one or more subcomponents is known, the sensitive nature of such sensors discourages a skilled person from separating functions because it can lead to a detriment in performance and/or reliability of the apparatus. Moreover, such sensitive and expensive apparatus is often reserved for laboratory use, or other controlled conditions and the use of specialist devices in uncontrolled environments, such as field use, further dissuades modification. A device having sensors and a conductive grid placed thereover is known from <CIT>, while <CIT> discloses a microelectrode array (MEA) plate joined to a biologic culture plate having a plurality of culture wells.

It is therefore an aim of the present invention to provide an improved component having a sensor, which is configured to inhibit damage to the sensor from, for example, electrostatic discharge (ESD). This component is modular such that it can be removably connected to a receiver to form a device. The device can then be removably connected with an apparatus to enable the data from the sensor to be read and analysed. Alternatively, the component can be removably connected directly to and from the apparatus. The invention generally resides in a such a modular component. Alternatively it can be supplied as a kit having a component and a receiver, or a component, receiver and device.

Generally, the invention resides in a component configured to removably engage with a receiver, the component having an array of electrodes for engaging with a corresponding array of connectors on a receiver. A plurality of electrodes of the array, which can be the majority of said electrodes on the array, are electrically connected to a corresponding well. To inhibit any detriment to the performance of a sensor configured in the well the array of electrodes is guarded, with a structure, against uncontrolled or unregulated voltages, such as an electrostatic discharge (ESD). The structure, alone or in combination with the component as a whole, functions to electrically encapsulate the wells, at least in part, from uncontrolled voltages.

According to one aspect of the present invention, there is provided a component in accordance with claim <NUM>.

The component has a conductive structure, that may appear like a matrix, configured across the array in a manner that enables an electrical connection between the array of electrodes and an array of connectors of a receiver, wherein the conductive structure is configured to inhibit an electrostatic discharge (ESD) conducting across the well and/or direct an ESD away from the well through the conductive structure. In other words, the connectors of the receiver, which extend from receiver to connect with the electrodes, may extend through the conductive structure. In that case, each connector on the receiver reaches an electrode on the component by passing between and past walls of the conductive structure.

The common electrode is arranged to be in contact with the fluid in the common chamber. The conductive structure can be electrically connected to the common electrode. The membrane can be an amphipathic bilayer. The component can be provided with a conductive fluid in the common chamber and fluid in the plurality of wells. A membrane can be formed across the plurality of the wells separating the fluid in the common chamber from the fluid in each of the plurality of wells. The conductive structure is configured to inhibit an electrostatic discharge passing across or via a sensor or a membrane via the well and/or direct an electrostatic discharge away from a sensor or a membrane. When the membrane is formed across the plurality of wells, the fluid contained in the wells are separated from each other.

The conductive structure can be connected to the fluid in the common chamber to inhibit a potential difference occurring across the well or membrane.

The component can be substantially planar, extending from a proximal to a distal end. The array of electrodes can be configured between ends of the component. Alternatively, the array of connectors can be located at one of the ends of the component.

The array of electrodes can be mounted upon a substrate, such as the substrate used to for the wells. Alternatively, the electrodes and/or wells can be formed on a printed circuit board (PCB). A PCB can be cheaper and quicker to manufacture.

The sensor can have a nanopore incorporated therein. The nanopore can be biological. The fluid can be a liquid, which can form a lipid bilayer across a well. The sensor can have a nanopore connecting a cis and trans region within the component. The well can support a membrane. The well can be implemented in a solid-state membrane and have a nanopore in said well. The nanopore can be a biological nanopore or a synthetic nanopore.

The component can have a membrane formed across a well or all of the wells. The membrane can be a lipid-bilayer. The conductive structure can receive ESD events and dissipate the energy from an ESD to inhibit damage to the sensor and/or membrane.

The conductive structure may have apertures or frames through which connectors of a receiver extend to contact the electrodes. The conductive structure can be a web or net, mounted on at least a portion of the substrate.

The conductive structure can inhibit contact with the electrode, particularly with part of the body such as a finger or gloved finger. However, contact of the electrode can occur and should a finger or gloved finger contact the electrode then the dimensions of the electrode are such that the conductive structure is also contacted. In other words, contact with the electrode alone is inhibited.

The component can also have a membrane formed across a plurality of the wells. The conductive structure can be configured to inhibit an electrostatic discharge passing across the sensor or a membrane via the well and/or direct an electrostatic discharge away from the sensor or a membrane.

The component can have a body that surrounds, encompasses or encloses the well, and the conductive structure is connected to the body such that they have the same potential difference. In other words, the body and conductive structure can function as a ground plane for the component. In use, the conductive structure functions to protect the well and, when a membrane is formed across the well an ESD to the body of the conductive structure is inhibited from passing through the well.

Each well can have a fluid, such as a liquid, contained therein in contact with the membrane provided across each well corresponding to respective electrodes of the array wherein the conductive structure is connected to the fluid reservoir providing fluid to the well to inhibit a potential difference occurring across the well or membrane. The conductive structure can be electrically connected to the body of the components to inhibit a potential difference or voltage across the sensor and/or membrane.

The component can be supplied with or without a fluid. If supplied without a fluid and the membranes pre-configured then the component can be said to be configurable to inhibit damage to the membrane and/or sensor.

The common sample chamber can contain an ionic fluid in contact with the common electrode. The fluid can provide a direct electrical connection between the array of connectors and the common electrode provided in the upper sample chamber containing fluid. An ESD can dissipate across the array as a whole thus minimising its effect. The effect of a charge applied to the conductive structure upon sensor components, such as the membrane, in the well or well can is inhibited or minimised because the conductive structure and the fluid are connected via the common electrode, at least, and reside at the same potential thus inhibiting a voltage passing across the well.

The array of electrodes can be arranged on the substrate and the conductive structure can be mounted on the substrate. The array of electrodes mounted on a substrate can define a plane and the conductive structure can extend parallel to said plane. The conductive structure can extend parallel to said plane above the substrate and above the electrode such that a void is created therebetween. The conductive structure can alternatively lie in the same plane as the substrate. Forming the conductive structure from the substrate can reduce cost because the conductive structure, or more specifically the walls of the conductive structure, can be formed at minimal material cost or minimal process time. If the substrate is non-conductive, a conductive layer can be added to at least a portion of the exposed surface of the conductive structure.

The conductive structure can extend from a plane defined by the electrodes. The array of electrodes can be arranged on a base of the substrate. At least part of the substrate can extend from the region between the electrodes to form a wall and the conductive structure can be configured on top of the wall. The conductive structure can be formed from the deposition of a conductive material in the region between electrodes.

The conductive structure can be configured to partially enclose each electrode. This can be achieved by the conductive electrode being formed on each side of the electrode while enabling the connector from the receiver to contact the electrode. The shape of the conductive structure, in cross-section, in a region distal from the electrode, can have a pointed edge or tip. Any charge from an ESD can, therefore, be concentrated at the point of the edge.

The conductive structure can be configured as a grid and extend in a planar direction, defined by the substrate between the electrodes.

The electrodes can be arranged in an array having a rectilinear pattern. The footprint of each electrode can be quadrilateral. The footprint can, alternatively, be one of a circular, diamondshaped or shape with <NUM> or more sides.

The cross-sectional profile of a wall of the conductive structure can be rectangular. The top of the wall can have a non-flat profile, such as a rounded form.

The walls, in cross-section can taper outward to minimise the aperture in the conductive structure or web or net such that contact with an electrode is further inhibited. In this way the surface area of the conductive structure can be increased to provide a greater contact area for an object such as a finger.

The pitch of the electrodes of the array can be between <NUM> and <NUM>. The pitch can be between <NUM> and <NUM>, and preferably between <NUM> and <NUM>.

The thickness of the walls of the conductive structure, in cross-section, can be between a minimum of <NUM> and minimum of <NUM>. The wall thickness can be between <NUM> and <NUM>.

Windows or apertures of the conductive structure through which the connectors extend can have rounded corners. Rounded corners can provide a reduced inductance path between the conductive structure and the common electrode.

The electrode array and conductive structure can be covered, at least in part, with a removable protective film or protective layer to inhibit antistatic discharge. The film can be configured to minimise any triboelectric charge that may be generated by the removal of the film, which is required before the component can be mated with the receiver. The film can inhibit a charge from conducting through, or in the region of, the well and/or sensor by the conductive structure. The film and the conductive structure, therefore, can function synergistically.

In another aspect, the invention resides in a kit in accordance with claim <NUM>.

The conductive structure can be connected to the conductive fluid in the sample chamber to inhibit a potential difference occurring across the well or membrane formed between the fluid in the sample chamber and fluid in a well, such that when a conductive fluid occupies the sample chamber an ESD is inhibited from conducting through, or in the region of, the well and/or sensor by the conductive structure.

The wells of the component can be provided with a pore for reading the properties of nucleotides passing through the pore. The pore can be a nanopore in the membrane between the fluid in the sample chamber and the fluid in at least one well.

The conductive structure can be formed as a grid having a plurality of apertures. There may be an aperture aligned with each mating connector and electrode.

The invention is discussed below, by way of example only, with reference to the following figures in which:.

<FIG> shows an apparatus <NUM> having a removably detachable device <NUM> having a receiver <NUM> and a component <NUM>. The device is removably detachable from a base <NUM> of the apparatus <NUM>. The various parts of the apparatus can be provided as a kit. The component <NUM> can be disposable. The device <NUM> can be inserted and removed from the base <NUM>. The component <NUM> can be inserted and removed from the receiver <NUM>.

In <FIG> the component <NUM> is shown positioned above the receiver <NUM> prior to insertion. When inserted, the component and receiver are mechanically connected and secured by a latch <NUM> and a recess <NUM>, which are located at the ends of the receiver. Electrically, the component and receiver can connect via an array of electrodes <NUM> on the component <NUM> and a corresponding array of connectors <NUM> of the receiver <NUM>. The body of the component <NUM> is typically made of a plastic material having a degree of elasticity. The plastic material may for example be polycarbonate.

The component <NUM> can be disposable and, by way of example, has a disposable flow-cell located therein. The flow cell can be equivalent to that discussed in <CIT>, wherein the component is configured to be a removable low-cost component, which can be disposed of after a single use. This is achieved by configuring more expensive components of the device <NUM> within the receiver <NUM>. The low-cost component makes it feasible to perform multiple experiments with different flow-cells relatively cheaply. The base <NUM> can house the electronics and cooling configuration for the overall apparatus <NUM>. The receiver <NUM> can house further electronics not included in the base <NUM> and functions as an adaptor to receive the component <NUM>.

Electrical connections are known from <CIT>, providing an example of the usage of the `solder bump' approach that provides an electrical connection to a layer of amphiphilic molecules. <FIG> shows such a `solder bump' <NUM> connection, as disclosed in <CIT>, connecting to a via <NUM> that passes through a substrate <NUM> to reach a well electrode <NUM> located at the bottom of a well <NUM>. The solder bump <NUM> enables a permanent connection with a seat <NUM> that is connected to a microprocessor or similar controller (not shown).

The well <NUM> is formed in the substrate <NUM> of non-conductive material and can be used to form or support a layer of amphiphilic molecules. In use, an aqueous solution can be introduced to the well <NUM>, and region therearound, such that a layer of amphiphilic molecules is formed across the well <NUM> separating the aqueous solution in the well <NUM> from the remaining volume of aqueous solution above the well. The arrangement of the well <NUM>, the well electrode <NUM> and additional circuitry (not shown) enables measurement of electrical signals across a layer of amphiphilic molecules. The well electrode can make electrical contact with the aqueous solution in the well <NUM>.

<FIG> are examples of a well <NUM> forming part of a sensor array, as respectively disclosed in <CIT> and <CIT>, describing a well <NUM> is formed in a material <NUM> such as SU-<NUM> forming a body, and many wells <NUM> may be formed in close proximity within the material to form an array of sensor wells. These wells <NUM> allow measurement of electrical signals across the layer <NUM> of amphiphilic molecules by connection of an electrical circuit <NUM> to the contacts <NUM> and <NUM>. <FIG>, known from <CIT>, shows a layer <NUM> of polar medium forming a meniscus interface 34a on a membrane <NUM> that protrudes into the wells <NUM> to contact a polar medium. A common electrode <NUM> arranged above the material <NUM> to make electrical contact with the layer <NUM> of polar medium once it has been provided. The ratio of the volume of fluid in a well <NUM> to the volume of the fluid in the layer above that forms the polar medium <NUM> can be between about <NUM>:<NUM> about <NUM>:<NUM>. <FIG>, known from <CIT>, shows a schematic cross section through another microcavity or sensor well <NUM> of a sensor array. In practice, an array of such sensor wells <NUM> formed in a body will be provided in a component of an apparatus and further comprise a cover over the surface of the body, to define a cavity between the cover and the body. An electrode (not shown in <FIG>) is arranged in the cavity for connection to the electrical circuit, and acts a common electrode for the wells in the array.

The well <NUM> forms part of a sensor, and the sensing components must communicate with a reader or microprocessor. In the present invention these wells reside in the component <NUM> and must electrically communicate with a reader on the receiver <NUM> and/or base <NUM>.

Removable connections, or non-permanent electrical connections are known, by way of example, from <CIT>, suitable for an array of electrical connections in such a way that the component parts can be attached and detached, and optionally reattached thereafter, without requiring extreme conditions (whether chemical or environmental) to trigger the connection or disconnection.

While removably detachable electrical connections are known the inventor has realised that conventional connections for parts such as the component <NUM> and receiver <NUM> can be improved. In particular the interface can be improved to provide an additional layer of protection to the well <NUM> and any sensor or sensing component residing or formed in such a well <NUM>. The interface that is connected to the wells on the component is sensitive to mechanical and/or electrical shock.

<FIG> shows, by way of example, one well <NUM> of a sensor array having an array of electrodes <NUM>. Each well <NUM> is connected through one of the electrical connectors in the array <NUM>. A pad <NUM> is provided to enable connection, via a via <NUM>, to a well electrode <NUM>. The pad <NUM> can be made from any conductive material, such as for example gold, copper or platinum. The substrate <NUM> functions as an insulator and is around <NUM> thick. The insulator can be made of silicon or glass, for example. The substrate in alternative examples of the invention can be conductive and provided with additional layers of insulating material or dielectric in order to configure pads, vias and and other such components.

<FIG> show the receiver <NUM> adjacent the component <NUM> with a portion (five wells <NUM>) of the electrode array <NUM> aligned with an array of connectors <NUM>. When connected, and the component is configured for use, signals detected by the well electrode <NUM> in the well <NUM> can be read. Signals pass from the well <NUM> via the well electrode <NUM> through the via <NUM> to the respective pad <NUM> of the electrode array <NUM>, which is configured to contact a connector on the array of connectors and provide a signal to a processer, typically an ASIC device. A common electrode <NUM> is electrically connectable through the polar medium <NUM> via a conductive diffusion layer <NUM> to each well <NUM> in order that a processor can control, though multiplexing, which of the well sensors is read or sensed.

<FIG> represents the configuration shown in <FIG>, while <FIG> represents a configuration wherein an array is configured at the end of the component <NUM> for engagement with an array of connectors located, for example, in the recess <NUM> of the receiver <NUM>.

The invention is particularly suited to the protection of membranes formed over wells or wells that are susceptible to damage or rupture by uncontrolled voltages, such as ESD, flowing through the well or sensor. The membrane may be a layer formed from amphiphilic molecules such as phospholipids, which have both hydrophilic and lipophilic properties. The amphiphilic layer may be a monolayer or a bilayer. The amphiphilic layer may be a co-block polymer such as disclosed in<NPL> or <CIT>.

The membrane may comprise an aperture formed in a solid state layer, which may be referred to as a solid state pore. The aperture may be a well, gap, channel, trench or slit provided in the solid state layer along or into which analyte may pass. Such a solid-state layer is not of biological origin. Solid state layers can be formed from both organic and inorganic materials including, but not limited to, insulating materials such as Si3N4, A1203, and SiO, organic and inorganic polymers such as polyamide, plastics such as Teflon® or elastomers such as twocomponent addition-cure silicone rubber, and glasses. The solid state layer may be formed from graphene. Suitable graphene layers are disclosed in <CIT>, <CIT> or <CIT>. Suitable methods to prepare an array of solid state pores is disclosed in <CIT>.

A biological nanopore may be provided in one or more of the membranes providing a conduction pathway across each membrane which serves to fluidically connect fluid provided in a well of the well array with solution provided in an upper chamber. The nanopore may be a transmembrane protein pore derived from but not limited to alpha-hemolysin, anthrax toxin and leukocidins, outer membrane proteins/porins of bacteria, such as Mycobacterium smegmatis porin & lysenin. The pore may be derived from CsgG, such as disclosed in <CIT>. The nanopore may be provided in the aperture of a solid state membrane. Such pores are known as hybrid pores. The nanopore may be formed from DNA origami.

The device of the invention is particularly suited for estimating the sequence of a polymer analyte. The analyte may be for example a polynucleotide, a polypeptide or a polysaccharide. Measurement of the polymer may take place during translocation of the polymer through the nanopore under a potential difference applied across the nanopore. The measurement may be a measurement of ion flow through the nanopore during translocation.

Ionic solution may be provided in the wells in contact with each respective membrane and the electrode provided in each of the respective wells of the array.

The component <NUM> can be supplied with a polar medium forming a meniscus or membrane over the well <NUM>, having a nanopore located in the membrane of each well <NUM>. The meniscus cooperates with the well to form part of the sensor. Alternatively, the component can be supplied 'dry' and without a polar medium, which is added to the component before installation to the device <NUM> and prior to testing or analysis of a sample. Further still, the component can be configured with a solid-state membrane and/or solid-state.

The meniscus and/or sensors of the well are sensitive to uncontrolled voltages, such as ESD. The wells, therefore, must be protected by inhibiting a voltage discharge passing across or through the well. In use, the pads <NUM> of the array of electrodes <NUM> are exposed in preparation for engagement with the array of connectors <NUM> on the device. Although the component <NUM> can be connected to a device <NUM> without the pads being touched, they remain susceptible to accidental touch by, for example, a finger tip. In the field, which is the antithesis of controlled laboratory conditions, a user would typically remove a component from its packaging and manually place it in the receiver. The invention mitigates any detrimental effects of a user contacting the array of electrodes <NUM> with, for example, their finger tip.

<FIG> shows, for illustration purposes, an array of pads <NUM> of an array of electrodes <NUM>. A conductive structure <NUM>, or grid, is configured across the array of electrodes <NUM>. The conductive structure, or grid, includes a common pad <NUM> that is connected to the common electrode <NUM>. The grid <NUM> can form a mesh, or web, that is connected to the common electrode. The grid <NUM> is connected to the common electrode <NUM> by way of example for electrically connecting the grid to the polar medium <NUM> in the chamber above the wells.

Additionally or alternatively the grid can be connected to the polar medium <NUM>, or the chamber in which the polar medium resides - this connection can be by means of at least one of: a dedicated via; a wired or bonded connection to a portion of a substrate; an electrical connection through the body of the component <NUM>; or an electrical connection to the structure forming the chamber holding the polar medium <NUM>, which surrounds the wells <NUM> of the array. <FIG> shows a cross-sectional view of a section of the grid <NUM> positioned above the array <NUM>, while <FIG> shows the relationship between the grid <NUM> and the polar medium <NUM> or sample <NUM>. In the example shown, the grid extends from areas on the substrate between the pads, but does not contact the pads <NUM>, and extends above the surface of the substrate. In the example shown the grid forms a net across the surface. The grid, however, can be formed from walls surrounding one or more pads <NUM>. The grid <NUM> can be positioned across the array of electrodes shown in <FIG>, in which the array of electrodes <NUM> can be arranged on a surface between the ends of the component <NUM> and can be positioned across the array of electrodes <NUM> shown in <FIG>, wherein the array <NUM> is arranged at an end region or face of the component.

<FIG> shows an alternative example in which the substrate <NUM> is conductive and an insulating layer or dielectric surrounds the substrate in order that a well electrode <NUM>, via <NUM> and pad <NUM> can be configured on the substrate. The grid <NUM> can be connected to a conductive coating surrounding or covering a portion of the substrate or the body of the component <NUM>. In this way, charge passed to the grid is conducted and dissipated in to the dielectric between the grid and conductive surfaces formed on the dielectric, which can create a common field that affects both common and well electrodes.

The grid can also be connected to the ground plane of the component, and the device, once the component is installed in the device <NUM>. In other words, if the substrate is conductive and coated in a dielectric or insulator, the grid can dissipate charge into this capacitance, whose field affects both common and well electrodes.

The dimension of the pads and the surrounding grid is such that either (i) objects, such as a finger, are inhibited from contacting the array <NUM> because the grid functions as a barrier or (ii) if the array <NUM> is contacted by an object it first contacts the grid. Therefore, any charge accumulated on a user's hand, or tool they are holding, is inhibited from passing through the well <NUM> or well electrode <NUM> region if it approaches or contacts the component <NUM> in the region of the array of electrodes <NUM> because it is directed through or via the grid <NUM> to the common electrode <NUM>.

Because the grid <NUM> and polar medium <NUM> are electrically connected, energy transferred from an ESD to the grid and to the polar medium requires negligible work done such that the voltage across a well <NUM> is negligible. In use, the layer of polar medium <NUM>, which can contain a sample to be analysed, is electrically connected to the common electrode <NUM> via the conductive diffusion layer <NUM>. The grid <NUM>, common pad <NUM>, common electrode <NUM>, conductive diffusion layer <NUM> and polar medium <NUM> or sample have, therefore, negligible difference in potential between them if an ESD was applied to the grid. This is because the charge is distributed across these components, which inhibits any charge passing between an electrode pad <NUM> and the well <NUM> to the sample of polar solution when the grid is contacted or both the grid and a pad are contacted. Sensors and/or membranes formed or forming part of the well <NUM> are protected from an ESD to the array <NUM>. The grid <NUM> acts as a shield - mechanically and/or electrically - that is connectable to a substantially large volume of fluid i.e. the polar medium <NUM>. These elements of the component <NUM> are significantly larger, by at least <NUM> orders of magnitude, than the size of the wells <NUM> or the volume of fluid held in the wells. As described above, the ratio of the volume of fluid in a well <NUM> to the volume of the fluid in the layer above that forms the polar medium <NUM> can be between about <NUM>:<NUM> about <NUM>:<NUM>. In the example, the common cell chamber, or sample chamber for holding a polar medium <NUM> and associated common mediator chamber, has a volume of about 135ul. In the example, which has an array of <NUM> electrodes, <NUM> are occupied by fluid for forming a membrane between each well and the sample chamber above and the total volume of fluid in the wells is about <NUM>. The ratio in the example is about <NUM>:<NUM>. In this way, the grid and/or the volume of polar medium (which is significantly larger than all of the wells together) function as a buffer or insulator protecting the sensing elements of the wells and sensor elements therein from an ESD or similar uncontrolled charge. In other words, any uncontrolled charge or ESD is inhibited from conducting from a pad <NUM> to a well <NUM> because the grid <NUM> inhibits contact with the pad and/or inhibits contact with the pad without also contacting the grid such that either (i) a charge, such as an ESD, passes to the polar medium or sample to distribute the charge with such low energy consumption that there is negligible potential difference between the pads <NUM> and the well <NUM> or (ii) if the array <NUM> is contacted an ESD charge is inhibited from flowing across the well <NUM> because the grid <NUM> has been contacted such that the well <NUM> region and the grid have the same potential difference - the charge is already balanced.

In use, the component is packaged in material that inhibits the build up of charge to minimise the risk of damage to a sensor or membrane within a well <NUM>, which can occur if a pad <NUM> of the array of electrodes <NUM> is touched. In field use, outside of a controlled environment such as a laboratory, there are rarely facilities such as earth-points or earth straps to divert uncontrolled voltages or ESD away from the pads.

To illustrate the dimensions of the invention, by way of an example illustration, the tip of a finger <NUM> is shown adjacent the grid <NUM> in <FIG>. Should an object, such as a finger of a user, approach a pad <NUM> then contact with the pad is inhibited and, even if contacted, the finger would touch the grid before, during and after contact was made with the pad <NUM>.

After initial manufacture of the component <NUM> and before population with a conductive fluid, such as a polar medium <NUM>, the grid <NUM> is configured to protect any sensor that will subsequently be formed in the well <NUM>.

<FIG> and <FIG> are snapshots of CAD images of embodiments of the grid <NUM> positioned between the pads <NUM> and connected to the common pad <NUM>. The size of the array <NUM> is approximately <NUM> pads, equivalent to an array of about <NUM> pads by about <NUM> pads. The pitch between the pads is shown, by way of example, as <NUM>. The pad is approximately square with sides about <NUM> in length. The gap between the pad <NUM> and the grid is about <NUM>. The thickness of the grid wall is approximately <NUM>. The ratio of the thickness of the grid wall to the width of a pad is about <NUM>:<NUM>. The ratio can be between about <NUM>: <NUM> and about <NUM>:<NUM>. The distance between the walls of the grid, or sides of the opening can be sized to inhibit a finger time from being able to contact a pad without contacting the grid. By way of a guide, the maximum opening size can be about <NUM> from corner to corner of the pad.

<FIG> is a magnified view of the lower right-hand side of the array <NUM> in <FIG>. It is to be noted that the shape of the grid <NUM> in the region surrounding an individual pad corresponds or matches the shape of the pad. The shape of the grid in the area adjacent a corner of a pad is curved. The shape of the grid is configured to minimise the inductance between the common pad <NUM> and any point on the grid <NUM>.

A gap is provided between the pad <NUM> and the grid <NUM>. The grid has been illustrated in other Figures as an extension of the substrate, preferably grown from the substrate, upon which the pad <NUM> is formed, which cannot be appreciated from the plan view of <FIG> and <FIG>. The upper-most surface of the grid has a conductive surface that is connected to the common pad <NUM>.

Alternatively, the grid can lie flush with the surface of the array such that finger-contact with a pad is not inhibited but finger-contact with a pad <NUM> without touching the grid is inhibited.

The array <NUM> can additionally be covered by a protective antistatic tape (not shown) that can be removed from the array <NUM> on the component <NUM> prior to insertion and connection with the receiver <NUM>. Without the grid <NUM> such tape could generate a triboelectric charge when peeled from the array <NUM> and damage the sensing function in a well <NUM>. The tape, however, complements the function of the grid <NUM> because any triboelectric charge generated from its removal will not influence the sensing in the well because the tape is connected to the grid. The conductive structure is therefore covered, at least in part, with a removable protective conductive film or protective layer.

Mechanical connections, such as spring-leaf metal contacts located on the receiver <NUM> for engagement with the electrodes on the component <NUM> can be provided. <FIG> illustrates an example of the first array of connectors <NUM> with a pitch of <NUM>. <FIG> shows a closeup of the connectors <NUM> which are sprung loaded and provided in respective wells <NUM>. To increase their strength each connector tapers outwards towards its base. The connectors are <NUM> thick and project to height of <NUM> above the well. The connectors are advantageously sprung loaded and project from the base to facilitate their connection to the array of electrodes <NUM> under an applied force.

<FIG> shows a perspective sketch view of a portion of a section of the grid <NUM>. While <FIG> shows a cross-section indicating that the grid <NUM> is like a net resting upon legs or walls that extend from the substrate, <FIG> shows that the grid can have walls surrounding pads <NUM> of the electrodes. The examples shown herein have the grid surrounding every pad <NUM> on an array <NUM> but the grid can, alternatively surround groups of pads. Therefore, the grid can extend from areas on the substrate between the pads, but without contacting the pads <NUM>, and form a wall. The top of the wall can be coated with a conductive material, such as gold or platinum to conduct ESD away from the pads. Alternatively the grid can have a non-raised profile and be approximately in the plane of the electrode array.

The height of a grid above the substrate - whether in net form, or whether in the form of walls as shown in <FIG>, is determined by the height of the connectors <NUM>. In <FIG> the height of the contacts is about <NUM> and would typically be reduced when compressed against a pad when the component <NUM> and device <NUM> were mated. For example, after mating the height could be reduced by compression by <NUM>% to about <NUM>. The height of the grid above the surface, therefore, can be around <NUM> such that the grid was inhibited from contacting the array of connectors <NUM> on the device. During mating, the connectors <NUM> extend through the grid and between the net or between the walls to contact the pads <NUM>. The gap between the pad <NUM> and the walls of the grid <NUM> insulate the array of electrodes from the grid <NUM>.

As described above, the shape and formation of the grid is such that the inductance between the grid <NUM>, common pad <NUM> and common electrode <NUM> is minimised.

The array of electrodes <NUM> and/or grid <NUM> have been described as formed on a substrate <NUM> with conductive surfaces for the pads <NUM> and for connection to, for example, the common electrode <NUM>.

The purpose of the component is to provide a low cost single use device and in light of the teaching herein various low-cost manufacturing techniques are applicable to the examples. <FIG> show two examples, respectively, of an array of electrodes <NUM> for connection to a device <NUM> having a multiple layer and single layer substrate. In the example shown in <FIG> the density of wells and electrodes is high, and has been fabricated on a substrate having coatings for electrodes and vias etc..

Alternatively, the pads <NUM> and grid <NUM> or tracks can be formed on, or by using:.

By way of example, an inkjet printed, roll-coated digital microfluidic device for inexpensive, miniaturized diagnostic assays is known from a paper in the name of Dixon et al [Lab Chip, <NUM>,<NUM>, <NUM>].

In <FIG>, an array of electrodes <NUM> are arranged at the side of a component. In this example the component is formed on a multi-layer printed circuit board. The pads are printed on an exposed layer and surrounded by a grid <NUM> that can be connected to a common electrode (not shown in this Figure). Tracks <NUM> are shown as dashed lines because they are provided on another layer and lead from vias <NUM>, connected to the pads <NUM>, to wells <NUM> located on the other side of the PCB. Reducing the number of wells <NUM> can reduce the complexity of the structure required to package said wells and simplify the circuits required to connect the wells to a device <NUM> via the array <NUM>.

<FIG> shows a further simplified arrangement in which connections to pads <NUM> are arranged on single layer of substrate. The grid <NUM> continues to substantially surround the pads to inhibit damage caused by an ESD. In this particular configuration the single layer substrate and printed tracks enables the component to be formed on a device.

Like numerals in the Figures represent like features. The present invention has been described above purely by way of example, and modifications can be made within the scope of the invention.

Claim 1:
A component (<NUM>) configured to removably engage with a receiver (<NUM>), the component (<NUM>) comprising:
a substrate (<NUM>) comprising plurality of wells (<NUM>); a well electrode (<NUM>) located at the bottom of each well (<NUM>);
a common chamber above the wells (<NUM>) comprising a common electrode (<NUM>), wherein each well (<NUM>) forms part of a sensor for receiving a fluid, wherein a membrane (34a) is formable across each well (<NUM>) to separate fluid in the well (<NUM>) from a fluid (<NUM>) in said common chamber, and wherein the common electrode (<NUM>) is arranged to be in contact with the fluid (<NUM>) in the common chamber; and
an array of electrodes (<NUM>) configured to removably connect with a corresponding array of connectors (<NUM>) on the receiver (<NUM>), wherein each of the electrodes of the array (<NUM>) are electrically connected via a respective via (<NUM>) through the substrate (<NUM>) to a respective well electrode (<NUM>),
characterised by a conductive structure (<NUM>) configured across the array of electrodes (<NUM>) in a manner that enables an electrical connection to be made between the array of electrodes (<NUM>) and the array of connectors (<NUM>) of the receiver (<NUM>), and configured to inhibit an electrostatic discharge conducting across the well (<NUM>) and/or direct an electrostatic discharge away from the well (<NUM>) through the conductive structure (<NUM>).