Wireless sensor and data logging device

Abstract

A wireless sensor and data logging device includes an integrated circuit 8 with wireless communication, sensor and data logging capability, a rechargeable printed battery and dual coil system for wire

Description

Field of the invention This disclosure relates to a wireless communication device incorporating sensor and data logging capabilities and powered using an integrated power source. This type of embodiment is sometimes termed a 'smart label' or 'smart tag'. Background of the invention Wireless communication to devices has been widely adopted by consumers with the advent of smart phones, laptop computers and peripherals. Near field communication (NFC) is one such type, and this employs electromagnetic induction between two loop antennas. NFC is commonly used to exchange information over short distances. Applications include credit payment devices, sensing environmental conditions, medical diagnostics, and inventory tracking. Summary of the invention The present disclosure is an embodiment consisting of flexible printed electronic conductors, near field coil inductive antennas, integrated circuit and silicon components, and a printed battery. This type of embodiment is sometimes termed 'hybrid flexible electronics' as it brings together electronic silicon chip components usually mounted on rigid circuit boards to flexible circuits which are laid down by direct printing or otherwise onto flexible substrates. An integrated circuit capable of sensing, measuring, logging data, and communicating wirelessly is itself integrated into a device manufactured using hybrid flexible electronics technology. A printed battery is included, as are dual coil antennas for NFC and charging the battery. The embodiment forms a fully assembled and sealed sensing and logging device which can be programmed and read using wireless reader devices and smart phones. The device is capable of being reset and reused as the battery can be charged by NFC or direct electrical connection. Brief description of drawings Figure 1 illustrates an embodiment showing antenna coils, conductive tracks, silicon electrical components and bipolar printed battery with co-planar co-parallel anodes and cathodes on a first substrate layer. Figure la illustrates the embodiment with an adhesive layer laminated on top with cut outs for the silicon components, test points, and for the battery electrolyte. Figure lb illustrates the embodiment with a barrier layer covering the battery. Figure lc illustrates the embodiment with a label cover with cut outs for test points. Figure Id illustrates the embodiment underside with a support rib and cover layer. Figure 2 illustrates an embodiment showing antenna coils, conductive tracks, silicon electrical components and bipolar printed battery with co-planar co-facial anodes and cathodes on a first substrate layer. Figure 2a illustrates an exploded view of the bipolar printed battery with co-planar co-facial anodes and cathodes. Brief description With reference to Figure 1, a near field communication coil 1 connected to an integrated circuit (IC) silicon chip 8 whereby connection is tracked over a dielectric bridge 3 and which are attached to a first substrate layer 13. A near field charging coil 2 with dielectric bridge 4 is connected to the battery by connector track 9 and co-planar bipolar battery connector 10 at terminals 10a and 10b attached to substrate 13. The battery is made from a three cell coplanar bipolar construct consisting of three pairs of cathodes 11 and anodes 12 linked via the bipolar battery connector 10 attached to substrate 13. This bipolar printed battery design with co-planar co-parallel anodes and cathodes is disclosed in prior art, U.S. Pat. No. 9,553,330. The anode and cathode size and relative proportions are designed to meet specific power and performance requirements. The connector tracks 9 attached to substrate 13 are linked to the coils 1, 2, the silicon chips 5, 6, 7, 8 and bipolar battery connector 10 at terminals 10a and 10b, and are used to transfer battery power from the battery to the IC 8, to transfer power from the NFC reader, and also to connect, communicate and transfer data to the IC 8 at connection points defined by and intersecting the IC 8, Figure 1. Diode silicon chips 5 and 6 are positioned in breaks in the connector track 9 and attached to substrate 13 and direct the flow of electrical energy from the near field charging coil 2 to the battery cathodes 11 and anodes 12. A light emitting diode (LED) silicon chip 7 maybe positioned in a break in the connector track 9 and used to indicate charge current is flowing and for providing an amount of voltage regulation. Figure la illustrates the adhesive layer 14 covering the elements illustrated in Figure 1, and with three cut outs for filling with electrolyte 22 covering the three cell battery cathodes 11, anodes 12 and space between each to allow current to flow; also cut outs for the silicon elements 5, 6, 7, 8, and cut outs for the test points 16, 17, 18, 19, 20, 21. The adhesive layer 14 isolates the electrolyte separately from each of the three cells which are therefore only connected electrically by bipolar battery connector 10. Figure lb illustrates the position of a barrier film 23 which covers the electrolyte 22 over the three cell battery cathodes 11, anodes 12, perimeter and areas around and between. Figure 1c illustrates the position of a cover film 24 with cut outs 25 exposing the test points 16, 17, 18, 19, 20, 21. Figure Id illustrates the position of an optional structural support rib 26 which is held in place by a bonded cover film or adhesive laminate 27, of a thickness to increase rigidity at the silicon components bonded attachments. With reference to Figure 2, a near field communication coil 1 connected to an integrated circuit (IC) silicon chip 8 whereby connection is tracked over a dielectric bridge 3 and which are attached to a substrate 13. A near field charging coil 2 with dielectric bridge 4 is connected to the battery by connector track 9 and bipolar printed battery with co-planar connectors 28 and 29 attached to a lower face plane first substrate layer 13. Connectors 28 and 29 therefore also form the battery connector terminals. The battery is made from a two cell bipolar printed battery with co-planar cofacial anodes and cathodes consisting of two pairs of cathodes 31, 34, and anodes 30, 35, linked via the bipolar battery connector 37 which is made from a conducting layer on an upper face plane second substrate layer. On the same lower face plane substrate 13 the first anode 30 and second cathode 31 are printed over connectors 28 and 29, respectively. The adhesive layer 36 is designed to contain the electrolyte and insulate adjacent anode and cathodes from one another. Figure 2a shows and exploded view of the two cell bipolar printed battery with co-planar co-facial anodes and cathodes. Anode 30 printed on connector 28 is covered with electrolyte 32 which is contacting co-facial cathode 34 and contained and separated by adhesive 36. Cathode 34 is printed on bipolar battery connector 37 which is printed together with anode 35 adjacent and thereby connected electrically as a bipolar configuration on the upper face plane. Electrolyte 33 covers anode 35 and the co-facial cathode 31 and contained and separated by adhesive 36. Cathode 31 is printed on connector 29. Adhesive 36 may be extended over the entire structure with cut outs for the silicon elements as shown for adhesive 14. This two cell bipolar printed battery therefore has co-facial anodes and cathodes separated by electrolyte and co-planar cathodes and anodes separated by adhesive and a bipolar battery connector on the upper face and separated by adhesive on the lower face. An array of multiple cells of two, three or more can be arranged where an even number of cells have battery terminal connectors on the same face plane, and odd number of cells have battery terminal connectors on the opposite face plane. This disclosure describes a sensing and logging device powered by a flexible printed bipolar battery with wireless communication and wireless charging. The device is cable of being operated by a smart phone or other NFC reader with a software application when they are positioned closely to each other in typical near field distance ranges. The software application can be designed for particular IC's and manage the various tasks such as programming, reading and transferring data, battery charge management, and for device diagnostics such as battery power indication. A dual coil system is employed, where a coil 1 is designed and assigned for communication and a coil 2 designed and assigned for inductively charging the printed battery. The coils are also capable of providing power to the IC during communication and charging processes. The alternating inductive current sent to the coil by the charging device is rectified to near direct current by the two diodes 5 and 6. The coils dimensions and number of turns are designed to be compatible with NFC and battery charge power. For a particular application four coil 1 turns and seven coil 2 turns are employed, Figure 1. The charging coil 2 can be designed to achieve a target voltage and current for different batteries or IC power requirements. The NFC coil 1 can be used to programme the IC and to read data from the IC, and also to power certain IC's which have this capability through the antenna circuit. The coils are assembled such that electrical connection is tracked over a dielectric bridge 3 for coil 1, and dielectric bridge 4 for coil 2, to enable connection to the electronic components 5, 6, 7, 8 on the same plane. An LED 7 can be employed as a visual indicator for charging as well as offering an amount of voltage and power regulation for the charging process. The IC 8 has an embedded wireless interface, sensors, and a direct battery connection. The sensor can be read wirelessly in passive mode, as well as when powered by a battery in active mode when logging is enabled. The battery is printed on the same substrate 13 and connected directly by means of the connector tracks 9 and bipolar connector terminals 10a and 10b and is designed for simpler manufacture. Substrate 13 may be selected from a range of commercially available material films of various dimensions, for example 100 micron thick polyethylene terephthalate (PET) with area dimensions 64 mm by 84 mm defining a required device size. The coils land 2 and conductive tracks 9 may be formed by screen printing silver or other conductive paste or by other conductive material deposition processes. The dielectric bridges 3 and 4 may be formed by screen printing dielectric or other insulating paste or by applying an insulating film or by other deposition process for applying insulating material. The printed bipolar battery elements 10, 11, 12, 14, 22, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37 may be formed by screen printing conductive, cathode, anode and electrolyte pastes, or by other deposition methods. The adhesive layer 14 and 36 may be printed using screen printable adhesives or prepared from patterned adhesive film, for example 0.2 mm thick double sided pressure sensitive adhesive film with release liners. The barrier film 23 may have moisture barrier properties, for example aluminium coated 0.01 mm thick PET. The silicon elements 5, 6, 7, 8 may be attached using a conductive adhesive, for example anisotropic silver conductive adhesive, which is deposited onto the connector tracks 9 under the silicon elements. The silicon elements 5, 6, 7, 8 may have conformal coatings or films covering and extending beyond their area to seal or improve bonding and connectivity to the substrate or conductive connector tracks. The embodiment may be coated in additional protective films to be compatible with a range of differing environments and use cases. For reliable sensor data logging the battery should provide continuous power for the duration of the logging event, or otherwise have a means to be recharged. The rechargeable battery permits the logging device to be reset and reused, and for data to be recovered in instances where the battery became depleted. The logging device can be recharged by a range of wireless charging devices including smart phones and their wireless charge pads, and bespoke wireless chargers. The drawings illustrated in this disclosure illustrate a wireless communication format using near field energy in a frequency range centred on 13.56 MHz. The design shown in Figure 1 is compatible with a NHS3100W8 IC manufactured by NXP which would form the IC 8. The NHS3100W8 chip measures and records temperature and time data which is logged in the chips memory. The embodiment forms a fully assembled and sealed sensing and logging device, which can also be termed a smart label or tag, which can be programmed and read using wireless reader devices and smart phones with a suitable software application. The smart label is capable of being reset and reused as the battery within can be charged by NFC during the reading event, or on a near field charger, or by direct electrical connection. The smart label can be programmed and stowed with the items that require their temperature or surrounding temperature to be known. The smart label may be used on its own or packaged in a protective container, for example in a sealable foil pouch forming a barrier to moisture or electromagnetic radiation. Existing or future IC's may be adapted by altering the connector design at IC 8. Similar embodiments where the coils are replaced with wireless antennas for communication at other wavelengths and for energy harvesting are obvious to those skilled in wireless electronic engineering. The co-planar bipolar battery design is disclosed in prior art, U.S. Pat. No. 9,553,330, and has the advantage of all the battery cell elements positioned on the same face plane. Other thin layer battery and printed battery designs may be used in this wireless communication sensing and data logging device. Figure 2 shows a further development of the co-planar bipolar design where the anode and cathode are co-facial as opposed to co-planar, and this is termed a bipolar printed battery with co-planar co-facial anodes and cathodes, while maintaining the bipolar connection design. This format has the benefit of lowering the battery internal cell resistance, for applications requiring higher power. This co-facial bipolar design can also be configured with the connector terminals on the same face plane for easier integration into the power circuit, Figures 2 and 2a. Multiple co-planar co-parallel, or co-facial, bipolar cell arrays can be assembled in a linear series chain or in other series chain geometries such as orthogonal, meandering serpentine, single or double spiral.

Claims

What is claimed is:

1. A wireless sensor and data logging device, comprising:a first substrate layer;a dual inductive coil system for wireless communication and battery charging;an integrated printed bipolar rechargeable battery;an integrated circuit with sensor, data logging, and wireless communication capability;battery connector terminals on the same face plane as main circuit;electrical current rectifier diodes;charging indication and voltage regulation light emitting diode;wherein the electronic elements, conductive circuit tracks and printed battery are on the same face plane that is the first substrate layer.

2. A wireless sensor and data logging device, comprising:a first and a second substrate layer;a dual inductive coil system for wireless communication and battery charging;an integrated printed bipolar rechargeable battery;an integrated circuit with sensor, data logging, and wireless communication capability;battery connector terminals on the same face plane as main circuit;electrical current rectifier diodes;charging indication and voltage regulation light emitting diode;wherein the electronic elements, conductive circuit tracks and part of the printed battery are on both the same face plane that is the first substrate layer, and part of the printed battery is on the second substrate layers face plane.

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