Abstract:
A probe assembly and a method of manufacturing a probe assembly. In one aspect there is a method of manufacturing a probe assembly comprising providing an electrode carrier carrying a plurality of electrodes, the electrode carrier comprising a top wherein the plurality of electrodes are exposed relative to the top and a bottom having a plurality of electrical contacts in electrical communication with the plurality of electrodes respectively; moulding a body around the electrode carrier to retain the electrode carrier whilst leaving the plurality of electrodes exposed. The invention also extends to a biomass monitoring system comprising a flexible enclosure including a probe assembly and support arrangement for receipt of the probe assembly in an engaged configuration.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119 to GB1607890.9, filed in Great Britain on May 5, 2016, which is incorporated by reference herein in its entirety. 
       BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    This invention relates generally to a probe assembly, and more particularly to a method of manufacturing a probe assembly. The invention is particularly suited, but not limited to, use in probes for biomass monitoring applications. 
       Description of the Related Art 
       [0003]    Commercial-scale biomass cultivation requires the constant monitoring of biomass production. Electrical properties of biomass can be measured by special designed probes. The modern trend for disposable bioreactors created recently a need for single-use probe systems. Single-use probes are secured to single-use flexible bags that contain the biomass, and the probe electrodes create and measure the electric field in the culture and provide data about the process. The increasing demand for large volumes of single-use probes requires a method of mass production for probes that will allow fast ramp up and increased production yield. The existing method of manufacturing probes is manual, slow and unable to cover current demand as probes are assembled one by one by workers resulting in increased rates of defects, production variability and low production yield. 
         [0004]    Existing probes designs present additional challenges in positioning them correctly in a monitoring system which while in use is typically arranged to rock the flexible bag in order to agitate the biomass. A probe and a monitoring system have to be aligned for engagement and secured. This is difficult to achieve due to the inherent flexibility of the bag and the difficulty in holding and engaging the probe. 
         [0005]    Furthermore, the rocking motion of the bag in combination with existing probe design can lead to loosening of electrical interactions between opposing sides of the probe resulting in additional noise in data collection. 
         [0006]    It is desirable to provide a fast to manufacture and reliable probe assembly. 
         [0007]    Such an improved solution has now been devised. 
       SUMMARY OF THE INVENTION 
       [0008]    It is an aspect of the present invention to provide a method of manufacturing a probe assembly comprising providing an electrode carrier carrying a plurality of electrodes, the electrode carrier comprising a top wherein the plurality of electrodes are exposed relative to the top and a bottom having a plurality of electrical contacts in electrical communication with the plurality of electrodes respectively; and moulding a body around the electrode carrier to retain the electrode carrier whilst leaving the plurality of electrodes exposed. 
         [0009]    Such a method provides a significantly improved method of manufacturing a probe assembly. 
         [0010]    The plurality of electrodes are preferably each formed of an elongate conductive element projecting from the electrode carrier, wherein a separation gap is provided between at least a portion of the electrode and the top of the electrode carrier wherein the moulding step introduces material of the body into the separation gap. This is beneficial as this ensures integrity of the probe whilst in use avoiding potential leak paths for the biomass that is typically present in a flexible bioreactor into which the probe will be mounted. 
         [0011]    Opposing ends of the plurality of electrodes are preferably located into corresponding electrode receiving formations in the electrode carrier. This step is carried out prior to the moulding step. 
         [0012]    The ends are beneficially fixed into the corresponding receiving formations. The ends may be soldered into the corresponding receiving formations. 
         [0013]    The electrode carrier beneficially comprises one or more sides provided between the top and the bottom, and wherein the body is moulded around some or all of the one or more sides. It is beneficial that the electrode carrier comprises four sides and preferably the body is moulded around all four sides. The sides may be encapsulated. It will be appreciated, however, that the body is preferably not moulded over the bottom. The electrode carrier however is effectively retained by the body. 
         [0014]    The bottom of the electrode carrier preferably comprises a holding formation and is held by the holding formation during moulding of the body, and wherein the method preferably further comprises a step of removing the holding formation after moulding. The holding formation may comprise an indent, opening or other formation in the bottom of the electrode carrier. This is held during moulding of the body. The holding formation is preferably removed after moulding. This may be achieved, for example, by filling. 
         [0015]    The body preferably comprises a primary flange having an abutment surface for engaging with a flexible enclosure. This abutment surface is adhered to a flexible bioreactor enclosure for use. It is preferable that the primary flange is integrally moulded with the body. 
         [0016]    According to a further aspect of the present invention there is a biomass monitoring system comprising a flexible enclosure defining a cavity, the flexible enclosure having an opening therein, the system further comprising a probe assembly comprising a top carrying a plurality of electrodes and a primary flange secured to the flexible enclosure to occlude the opening such that the plurality of electrodes are in communication with the cavity, the probe assembly further comprising a secondary flange spaced apart from the primary flange and defining a channel therebetween and a plurality of electrical contacts in electrical communication with the plurality of electrodes provided on a bottom of the probe assembly externally of the cavity; the system further comprising a support arrangement having a guide channel for receipt of the secondary flange in slideable engagement, the support arrangement further comprising electrical contact elements arranged to electrically communicate with the plurality of electrical contacts of the probe assembly in an engaged configuration. 
         [0017]    The primary and the secondary flanges are beneficially substantially parallel. It is beneficial that the slideable engagement is in an axis substantially perpendicular to an axis between the top and the bottom. The support arrangement preferably comprises a support surface for supporting the enclosure and the slot preferably projects substantially parallel to the plane of the support surface. As such, the flexible enclosure including the probe beneficially sit on the support arrangement. 
         [0018]    In the engaged configuration the primary flange is beneficially positioned externally of the guide channel. Accordingly, the secondary flange is retained in the guide channel whereas the primary flange is external of the guide channel. 
         [0019]    The guide channel beneficially comprises a width defined by a first and second side wall and a top and bottom, the top having an opening therein extending between opposing shoulders, wherein the opposing shoulders extend into the channel defined between the primary and secondary flange portions of the probe in the engaged configuration. 
         [0020]    The guide channel is beneficially open substantially perpendicular to the contact surface of the electrical contacts of the probe. The guide channel beneficially extends generally parallel to the active portion of the electrodes. 
         [0021]    The support arrangement is beneficially configured to retain the probe in the engaged configuration. This is important as during operation of the biomass monitoring system the support arrangement beneficially moves in a rocking motion to agitate the content of the flexible enclosure. As such, it is beneficial to retain the probe in the engaged configuration. This is preferably achieved through the electrical contact elements of the support arrangement being deflectably mounted and being arranged to bias the secondary flange into communication with the opposing shoulders. Accordingly, the electrical contact elements are beneficially in the form of spring loaded pins. 
         [0022]    The guide channel beneficially comprises a mouth, and the shoulders taper inwardly in a direction into the guide channel away from the mouth. This is beneficial in order to improve accessibility of the probe and the support arrangement and enables guiding of the probe onto the support arrangement. 
         [0023]    The secondary flange beneficially comprises a first and second flange portion, wherein the first flange portion and primary flange define a first channel and the second flange portion and primary flange define a second channel. Accordingly, in the engaged configuration two sides of the probe are retained by these support arrangements. 
         [0024]    The support arrangement is beneficially arranged to cause agitation of the flexible enclosure and probe in operation. The support arrangement beneficially is configured to rock to cause agitation. 
         [0025]    The probe assembly beneficially comprises an electrode carrier and a body, wherein the body comprises the primary and secondary flanges, and wherein the body is formed around the electrode carrier to retain the electrode carrier whilst leaving the plurality of electrodes exposed. 
         [0026]    The electrode carrier is preferably seated in the body, the electrode carrier comprising the plurality of electrical contacts, and a separation gap is defined between a portion of the plurality of electrodes and the electrode carrier, wherein the body extends into the separation gap. 
         [0027]    According to a further aspect of the present invention there is a probe assembly comprising a top carrying a plurality of electrodes, a primary flange for securing to a flexible enclosure and a secondary flange spaced apart from the primary flange defining a channel therebetween, the probe assembly further comprising a plurality of electrical contacts in electrical communication with the plurality of electrodes provided on a bottom of the probe assembly, the secondary flange arranged to slideably engage with a support arrangement. 
         [0028]    These together with other aspects and advantages which will be subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, will become apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which: 
           [0030]      FIGS. 1 a  and 1 b    are perspective schematic views of a probe according to an exemplary embodiment of the present invention; 
           [0031]      FIG. 2  is a schematic view of a biomass monitoring system including engaged probe according to an exemplary embodiment of the present invention; 
           [0032]      FIG. 3  is a schematic cross sectional view of a probe located in the biomass monitoring system according to an exemplary embodiment of the present invention; 
           [0033]      FIGS. 4 a , 4 b  and 4 c    are top, side and bottom schematic views of a probe according to an exemplary embodiment of the present invention; 
           [0034]      FIGS. 5 a  and 5 b    are perspective top and bottom schematic views of the electrode carrier forming part of a probe according to an exemplary embodiment of the present invention; 
           [0035]      FIG. 6  is a cross section of the electrode carrier of  FIG. 5 ; and 
           [0036]      FIG. 7  is a block diagram of an exemplary manufacturing process of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0037]    Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 
         [0038]      FIGS. 1 a  and 1 b    illustrates probe  16  comprising electrodes  20 , a probe body  18  and electrode carrier  37 . The probe  16  has a top  17  and bottom  19 . The probe body  18  is formed around electrode carrier  37 . Probe body  18  comprises primary flange  16 , neck  28 , and secondary flange  30 . The electrode carrier  37  comprises electrode body  38 , electrical contacts  22  for electrically communicating with the electrodes  20  and holding formation  24 . The plane of primary flange  16  and the plane of secondary flange  30  are substantially parallel. The middle part connecting the primary flange  26  and secondary flange  30  forms a neck  28 . 
         [0039]      FIG. 2  is an exemplary schematic representation of the use of the probe  16  positioned in a support arrangement  32  having a support surface  14 . The support arrangement  32  is configured to cause agitation of the biomass retained inside a flexible enclosure not shown in  FIG. 2  for clarity purposes. A guide channel  36  is formed to receive the secondary flange  30  and primary flange  26  is arranged to sit externally on the top of support arrangement  34 . The top surface of the primary flange  26  is adhered to a flexible bag (removed for clarity purposes). Guide channel  36  comprises a slot having a width  34  open outwardly and width  35  to receive and guide probe  14 . 
         [0040]    Referring to  FIG. 2  in combination with  FIG. 3 , the flexible enclosure  40  is adhered to the top surface of the primary flange  36 .  FIG. 3  represents a side view of the guide channel  36 , into which the probe  16  has been positioned. In this position the lower surface of the primary flange  26  abuts the support surface  14  that surrounds the guide channel  36 . Shoulders  44   a ,  44   b  of the support arrangement  32  project into the guide channel  36  beneath which the secondary flange  30  is received. Accordingly, the width of the outwardly facing opening  34  through which the probe projects when engaged is less than the width  35  of the guide channel  36  in which the secondary flange  30  is received. The direction of insertion of the probe  16  into the guide channel  36  is along an axis substantially perpendicular to an axis between the top and bottom of probe  16 . 
         [0041]    Electrical contact elements  48  are configured to electrically communicate with the probe electrical contacts  22 . Electrical contact elements  48  can be spring loaded pins. In an engaged position electrical contact elements  48  exert pressure on the secondary flange  30  of the probe to the retain probe in an engaged position. Electrical contact elements  48  can be deflectable and are arranged to bias the secondary flange  30  into communication with the opposing shoulders  44   a ,  44   b . Guide channel  36  is substantially perpendicular to the direction or deflection of the contact elements  48 . 
         [0042]      FIGS. 4 a , 4 b , 4 c    are top, side and bottom schematic views of a probe  16 . An injection moulding process may be used to form the probe body  18  around the electrode carrier  37 . The elongated electrodes  20  are left exposed in order that contact with the biomass is enabled when the probe is in operation. The bottom part of the electrode carrier  37  is also exposed to be allow the electrical contacts  22  to electrically communicate with the spring loaded contact elements  48  of the support arrangement  34 . As shown in  FIG. 4( b )  the neck  28  along with the primary flange  26  and secondary flange  30  define an engagement channel  29  for receipt of the shoulders  44   a ,  44   b.    
         [0043]      FIGS. 5 a  and 5 b    present an electrode carrier  37  comprising an electrode carrier body  38 , having a plurality (four in the exemplary embodiment) of elongated electrodes  20  positioned above the top of the electrode carrier body  38  and on the bottom are electrical contacts  22  and holding formation  24 . The holding formation  24  is grasped by the moulding machine. A separation gap  36  is present between at least a portion of the electrodes  20  and the electrode carrier body  38  top surface. During the moulding step, material of the probe is introduced to the separation gap  36 . Holding formation  24  is used to secure the electrical carrier  37  inside the mould during the (injection) moulding process. Electrical contacts  22  are located in the bottom of the electrode carrier  37  and are in electrical contact with the elongated electrodes  20  as further explained with respect to  FIGS. 3 and 4 . 
         [0044]      FIG. 6  is a cross sectional representation of the electrode carrier  37 . Electrode ends  20   a  extend in a perpendicular direction to elongated portions of electrodes  20 . The electrode ends  20   a  are positioned in corresponding electrode receiving formations  52  that extend into the electrode carrier body  38 . Receiving formations  52  are electrically connected to electrical contacts  22  positioned at the bottom of electrical carrier  37  by electrical connection lines  54 . Electrode ends  20   a  are inserted in a perpendicular direction relative to the top surface of the electrode carrier body  38 . The elongated top portions of the electrodes  20  are positioned in parallel to electrode carrier  37  top surface. Electrodes  20  are secured by soldering  58  in receiving formations  52  prior to a moulding step. When electrodes  20  are secured, the separation gap  36  is formed between electrodes  20  and the electric carrier body  38 . The separation gap  36  is filled with material to form part of the probe body  18  during the moulding step. 
         [0045]      FIG. 7  presents an overview of the manufacturing process for production of a probe according to an exemplary embodiment. Firstly electrodes ends  20   a  are secured or soldered in receiving formations  52  in the electrode carrier body  38 . The electrode carrier  37  is then placed inside a moulding machine and held in place by holding formation  24 . The probe body  18  comprising primary flange  26 , secondary flange  30 , neck  28 , and the separation gap  36  is filled by moulding. The holding formation  24  can then be removed post moulding, for example by filling with resin. 
         [0046]    It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be capable of designing many alternative embodiments without departing from the scope of the invention as defined by the appended claims. In the claims, any reference signs placed in parentheses shall not be construed as limiting the claims. The singular reference of an element does not exclude the plural reference of such elements and vice-versa. In a device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. 
         [0047]    The many features and advantages of the invention are apparent from the detailed specification and, thus, it is intended by the appended claims to cover all such features and advantages of the invention that fall within the true spirit and scope of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.