24, such that the device 10 can receive, hold, and wash up to four well plates at one time. Other embodiments of the device may be able to wash greater or fewer than four objects at once, but generally greater than one object in most efficient usage. For illustrative purposes, the arms of the rotor 20 are labeled with letters A-D to indicate the four different well plate positions. During the process of adding or removing well plates from the device and during the process of washing the well plates, the rotor 20 is typically rotated to four different angular positions. In each of these four angular positions, two of the opposing arms of the rotor 20 are aligned substantially vertically and the other two opposing arms are aligned substantially horizontally. That is, in each of these four angular positions, one well plate (A in FIG. 2) is in the top or 12 o'clock position, one well plate (B in FIG. 2) is in the right or 3 o'clock position, one well plate (C in FIG. 2) is in the bottom or 6 o'clock position, and one well plate (D in FIG. 2) is in the left or 9 o'clock position. In FIG. 2, the plate holder on the arm labeled A is in the top position, the plate holder on the arm labeled B is in the right position, the plate holder on the arm labeled C is in the bottom position, and the plate holder on the arm labeled D is in the left position,

Each plate holder 24 holds a single well plate during the wash cycle. In the illustrated embodiment, each plate holder 24 comprises a planar base and raised side and rear walls. The front edge of the plate holder 24 is not raised to enable a well plate to be slid horizontally into the plate holder 24 through the opening 15. Any suitable mechanism may be used to hold the well plate onto the plate holder 24. In the illustrated embodiment, a gripper bar 26 forms one raised side wall of the plate holder 24. One or more springs or the like (not illustrated) bias the gripper bar 26 toward the well plate to apply a restraining force, thereby sandwiching the well plate between the gripper bar 26 and the opposing raised side wall of the plate holder 24. Other embodiments of the device may use different mechanisms that apply forces to hold the objects in position on the rotor during rotation.

In the illustrated embodiment, the plate holders 24 are configured to receive well plates having a predetermined footprint (i.e., length and width), typically based on the ANSI/SLAS microplate standard (formerly called the SBS standard), but having a variety of different heights. Two different height well plates are illustrated in the figures—a “tall” well plate 18A and a “short” well plate 18B. Other embodiments of the device may allow for objects with different shapes, dimensions, and geometries to be held in position on the rotor. This may be accomplished through the use of specifically designed holders for specific objects, adapters, or other modular holding mechanisms.

The front panel opening 15 aligns with the top well plate position, such that a well plate is loaded into or removed from the plate holder 24 in the top position. After a well plate is loaded into the plate holder 24 in the top position (manually or by an automated material handling mechanism), the motor 32 activates and rotates the rotor 20 90° such that an adjacent plate holder 24 is now in the top position. (The rotor may be rotated clockwise or counterclockwise. The rotation of the rotor will be described herein only as clockwise for simplicity.) The amount of rotation of the rotor may be controlled by counting the steps of the stepper motor and/or by using one or more sensors to verify the position of the rotor. After the rotor 20 is rotated 90°, another well plate may be loaded into the plate holder 24 that is now in the top position. This may be repeated two more times until a well plate has been loaded into all four plate holders 24. Other embodiments of the device may load objects in locations or orientations other than the top position. A wash cycle (described below) may then be run to clean and disinfect the well plates. The cleaned well plates may then be removed from the device 10 in a similar fashion, that is, one at a time from the top position. Embodiments of the invention may enable the device to operate without all of the plate holders 24 loaded. If only two well plates are to be loaded, the rotor 20 may be rotated 180° to ensure that the well plates are loaded onto opposing (rather than adjacent) plate holders 24 for balancing purposes.

One or more sensors 96 may be used to detect the presence of a well plate in a plate holder. Any suitable number, position, and/or type of sensors may be used (including but not limited to optical, ultrasonic, infrared, mechanical, and/or magnetic sensors). A single sensor may be used, for example, adjacent the top position to detect that a well plate has been loaded prior to rotating the rotor 20 or adjacent the right side position (position B in FIG. 2) to detect the well plate after rotating the rotor 20. Alternatively, there may be a sensor at each of the four well plate positions (i.e., top, right, bottom, left).

The well plate in the top position may be sprayed with a fluid (e.g., cleaning solution, rinsing agent, etc.) by a fluid manifold 40. The fluid manifold 40 is positioned above the well plate that is in the top position and sprays fluid downward onto the top of that well plate. The well plates are positioned on the plate holders 24 such that the top openings of the cavities face outward (away from the center axis). In this regard, the top openings of the cavities of the well plate in the top position face toward the fluid manifold 40, thereby enabling the fluid sprayed from the fluid manifold 40 to enter the cavities of that well plate. The fluid manifold 40 has a generally rectangular prism shape, with a fluid input 42 on the top surface (the location of the fluid input may vary) and a plurality of fluid outputs 44 arranged in a matrix on the bottom surface. One or more pumps 98 may be used to pump the fluid to the fluid manifold 40 from a reservoir (not illustrated) via a hose (not illustrated). The pump 98 may be used to drive the pressurized fluid wash. Alternatively, pump 98 may be used to prime the lines (fill the tubes leading to manifold port 42 with fluid), and then compressed air may be used to provide a greater pressure fluid movement, as described below. A plurality of channels (not illustrated) defined within the fluid manifold 40 direct the fluid from the fluid input 42 to each of the fluid outputs 44. The fluid then sprays downward from the fluid outputs 44 toward the well plate in the top position. It is desirable that the fluid exit the fluid manifold 40 at a sufficient pressure to enter the cavities of the well plate with sufficient force to dislodge any materials within the cavities. The amount of fluid pressure needed may vary. A pressure regulator (not illustrated) may be used to set the wash pressure to different values as needed. The pump pressure (or air pressure of the fluid that is driven by air, as described below), as well as narrowing of the channels between the fluid input 42 and the fluid outputs 44 of the fluid manifold 40, provide the desired fluid output pressure.

In the illustrated embodiment, the fluid manifold 40 has 96 fluid outputs 44 arranged in an 8×12 matrix to correspond to the cavity arrangement of a conventional 96 cavity well plate. Different fluid manifolds with different numbers and arrangements of fluid outputs may be alternatively used to correspond to well plates having different numbers and arrangements of cavities. Such different fluid manifolds may be readily interchangeable within the device. Further alternatively, fluid manifolds having wider angle spray nozzles may be used such that there need not be a one-to-one correspondence between fluid outputs of the fluid manifold and well plate cavities. Other embodiments of the invention may use a spray nozzle or other dispensing mechanism, instead of the manifold described in this disclosure, to provide a jet of pressurized fluid or otherwise transport fluid to contact or interact with the object(s) being cleaned.

It may be desirable to spray air into the cavities of the well plate. Some of the above-referenced co-owned patents describe alternating spraying fluid and spraying air from the fluid outputs of the fluid manifold, and the mechanisms/methods described therein may be used in embodiments of the present invention. Similarly, pump 98 may be used to prime the lines (fill the tubes leading to manifold port 42 with fluid), and then compressed air may be used to provide a greater pressure fluid movement. The well plate washing device of embodiments of the invention may use the same or a similar method to spray air through the fluid manifold 40, using a pump 98 or otherwise pressurized air, to help clean the cavities and/or remove cleaning fluid from the cavities. The pressurized air flow may be generated from an appropriate source, such as a blower, fan, pump, vacuum, or air compressor. The device may alternate the spraying of the cleaning fluid and air or may spray air after spraying the cleaning fluid to help remove the cleaning fluid before the plates are rotated.

Because the cavities of well plates are only open on the top end, the cleaning fluid must both enter and exit the cavities through the open top end. Because of this, the fluid manifold cannot seal against the top of the well plate as there would be no way for the fluid to escape. In this particular embodiment of the device, to maintain the necessary spacing between the fluid manifold and the well plate, a spacer 46 is used. As best seen in FIGS. 10A and 10B, the spacer 46 comprises a top plate 48 to which the manifold is affixed, a bottom frame 50, and an arm 52 therebetween. As seen in the figures, the bottom frame 50 comprises an open rectangle that is sized and shaped to contact the outer edge of the top surface of the well plate to maintain the desired spacing while not obstructing the fluid flow from the fluid manifold 40 to the well plate. The spacer 46 of the illustrated embodiment maintains a 12 mm spacing between the bottom surface of the fluid manifold 40 in the top surface of the well plate, but any suitable spacing may be used. Any other suitable method to create the proper spacing may also be used.

The fluid manifold 40 is selectively movable up and down relative to the well plate in the top position. In the up position, the fluid manifold 40 is out of the path of the well plates, plate holders 24, and rotor 20 as the rotor 20 rotates. When the rotor 20 stops rotating, the fluid manifold 40 may be lowered into position to spray fluid at the well plate in the top position. Any suitable mechanism may be used to selectively raise and lower the fluid manifold 40. In the illustrated embodiment, the fluid manifold 40 is affixed (via the spacer 46) to a linear actuator 60 with selectively extendable and retractable arms 62. The linear actuator 60 extends the arms 62 to lower the fluid manifold 40 and retracts the arms 62 to raise the fluid manifold 40. Because well plates of different heights may be washed in the device 10, the stroke length of the linear actuator 60 must be sufficient to be able to lower the fluid manifold 40 to a low enough position to reach the top surface of the shortest well plates that may be washed in the device 10. In a preferred embodiment of the invention, a simple pneumatic linear actuator is used in which the arms 62 extend until the spacer 46 contacts the top surface of the well plate. When the spacer 46 contacts the top surface of the well plate, the linear actuator 60 will continue to try to extend the arms 62 and in this regard will maintain sufficient pressure to hold the fluid manifold 40 in position, despite the fluid spray applying an opposing force. It is desirable that the linear actuator provide enough force to maintain the position of the fluid manifold but not excessive force that might damage the well plate, the plate holder 24, the rotor 20, or any other components of the device 10. Because this mechanism automatically adjusts to any height well plate, it is possible to wash well plates having different heights in the same wash cycle. In alternative embodiments of the invention, a multi-position pressure-sensitive linear actuator may be used to raise and lower the fluid manifold to a plurality of different positions depending on the height of the well plate, however such an embodiment is significantly more complex. Any suitable sensor (such as a Hall effect sensor) or other mechanism may be used to verify that the fluid manifold 40 is raised to its fully retracted position such that the rotor 20 can safely rotate.

To protect the linear actuator 60 from exposure to fluids within the wash chamber 13, a splash guard 64 may surround the portion of the linear actuator 60 that is within the wash chamber 13. In the illustrated embodiment, the splash guard 64 comprises a square tube with a lower end that is affixed to the spacer top plate 48 (using any suitable method of affixation (such as welding) that prevents or limits fluid from reaching the linear actuator 60) and that projects upward through an opening 66 defined in the top surface of the housing 12. As seen in FIGS. 3 and 4, the splash guard 64 raises and lowers in conjunction with the fluid manifold 40 and the spacer 46. In this embodiment, a wiper gasket or the like (not illustrated) provides a fluid seal between the opening defined in the top surface of the housing 12 and the outer surface of the splash guard 64.

The lowermost panel of the sidewall 16 may include a drain 72, leading to a valve 74, which in turn leads to a hose or the like (not illustrated) for removing fluid from the device 10 as needed during and/or after a wash cycle. This drain may be positioned anywhere on the bottom face of the wash compartment and use any suitable geometry such that the drain hole is at the lowest point of the compartment and gravity causes fluids to move to the drain.

The housing 12 may include one or more UV transparent windows 78 to enable UV light from a UV light fixture 80 to enter the wash chamber 13 and to shine upon one or more of the well plates therein and/or one or more of the internal surfaces for sanitization purposes. The UV light fixture preferably emits UV-C light at a wavelength of 254 nm. In the illustrated embodiment, there are two opposing UV transparent windows 78 such that UV light shines directly on the well plates in the opposing side positions (position B and position D in FIG. 2). Although not illustrated, the UV light fixtures 80 will typically have a cover to block the UV light from shining anywhere except toward and through the UV transparent windows 78. This cover may be comprised of a preferably semi-cylindrical mirror to reflect light towards the window and plates. Some or all of the inner surfaces of the housing 12 may be UV-reflective (either inherently or due to an applied coating) to increase the dispersion of the UV light throughout the wash chamber 13.

One or more ultrasonic transducers 76 (four are illustrated) may be affixed to the housing 12 to impart an ultrasonic vibration to fluid pooling in the wash chamber 13 as desired during a wash cycle to assist in cleaning the well plates. In one exemplary embodiment, the ultrasonic transducers vibrate at 40 kHz. As illustrated, it may be desirable to affix the ultrasonic transducers to the bottom or lower portion of the housing, directed upward, as the bottom or lower portion of the housing will be in contact with the pooled fluid (the wash chamber 13 will typically only be partially filled with fluid, if at all) such that the illustrated location of the ultrasonic transducers will more efficiently impart an ultrasonic vibration to the pooled fluid. The ultrasonic vibration imparted to the pooled fluid creates a sonication bath via cavitation bubbles. The vibration and cavitation bubbles aid in cleaning a well plate that is submerged in the fluid. Other embodiments of the device may introduce ultrasonic waves through alternative modes, such as probes going directly into the cavities of the well plates in the top rotor position.

One or more fluid spray nozzles 70 may be positioned within the wash chamber 13 (two nozzles are illustrated in the figures). The spray nozzles 70 are used to introduce fluid into the wash chamber 13. The fluid introduced into the wash chamber 13 may be, for example, deionized (DI) water or a cleaning solution. One or more pumps 98 may be used to pump the fluid to the spray nozzles 70 from a reservoir (not illustrated) via hoses or pipes (not illustrated). The spray nozzle 70 may introduce fluid into the wash chamber 13 for at least two different reasons. First, the fluid may be introduced into the wash chamber 13 to at least partially fill the wash chamber 13 to be able to submerge at least the well plate in the bottom position (position C in FIG. 2) in the fluid as part of the wash cycle (optionally, the wash chamber 13 may be filled with enough fluid to submerge the well plates in three positions (the left, right, and bottom positions), all four positions, or two positions in an orientation where the rotor is rotated 45° from what is displayed in FIG. 2). Second, the spray nozzle 70 may enable the sprayed fluid to reach some or all of the internal surfaces of the wash chamber 13, thereby helping to clean those surfaces of any debris. In one embodiment, the nozzles may be 360° spray nozzles in order to spray fluid in a pattern that will allow for a single or more nozzles to clean all internal compartment and rotor surfaces. In alternative embodiments of the invention, a combination of tubing or nozzles may be positioned along the upper edges or faces of the compartment and direct fluid such that it flows down the inner walls of the wash compartment in a “waterfall” fashion.

It may be desirable that the device can conduct a self-clean operation of the wash chamber 20 and components within the wash chamber 20, in order to remove contaminants that may be introduced to the wash chamber 20 during a wash process and sanitize the space. To conduct a self-clean, the bath can be filled with reagent to a depth level such that the rotor 20 or parts mounted to the rotor are in contact with the reagent bath. The rotor 20 will then spin at high speed (typically 10-1000 rpm) in either or both directions, or in more complex movement patterns. When the rotor 20 or parts mounted to it collide with the reagent bath, it will forcibly splash and disperse the reagent throughout the wash chamber 13. A scoop (not illustrated) mounted to the rotor 20 may also be used to increase the volume and splash intensity of reagent that is displaced during this self-clean spin cycle. The UVC light (preferably 254 nm wavelength) from UV bulbs 80 may also be reflected and dispersed throughout the wash chamber 20 to sanitize the space.

The device 10 may comprise one or more heaters 100 to heat the air inside the wash chamber 13 for drying and/or disinfecting purposes. In one embodiment of the invention, a heating unit is mounted directly to the outer surface of the metal housing 12 to heat the housing 12. The air inside the wash chamber 13 will then be heated via conduction with the housing 12. In other embodiments of the invention, air will be heated external to the wash compartment and then be pumped into the compartment through any suitable pump, such as a blower or fan 102.

Referring now to FIG. 11, a control system of a well plate washing device is illustrated in accordance with embodiments of the invention. The well plate washing device 10 comprises a controller 90. The controller 90 may comprise a microprocessor, dedicated or general purpose circuitry (such as an application-specific integrated circuit or a field-programmable gate array), a suitably programmed computing device, or any other suitable means for controlling the operation of the device 10. The controller 90 may receive inputs from one or more user inputs devices 92, such as buttons, switches, knobs, keypad, bar code reader, magnetic scanner, RFID scanner, etc. This embodiment of the invention will primarily use a touchscreen LCD for user inputs. The controller 90 may provide outputs to one or more user output devices 94, such as lights, LED or LCD displays, sound generators (such as buzzers or beepers), etc. The controller 90 may receive inputs from one or more sensors 96, such as described above. The controller 90 may receive inputs from one or more temperature sensors 104. The controller 90 may control the extension and retraction of the linear actuator 60 and additional actuators in other embodiments. The controller 90 may control the opening and closing of the drain valve 74. The controller 90 may turn on and off one or more of the ultrasonic transducers 76, the pumps 98, the UV lights 80, heaters 100, and/or fans 102. As described above, the controller may control the motor and its movement patterns.

The well plate washing device of embodiments of the invention may be adapted to perform many different wash routines comprising many different steps in any suitable order. Some exemplary wash routines/steps are described herein for illustrative purposes but are not intended to be limiting. A high level workflow using a well plate washing device of embodiments of the invention may comprise the following steps: conducting an experiment/reaction using one or more new or cleaned well plates; transferring up to four used well plates into the well plate washing device, cleaning the well plate(s) of any experiment/reaction chemicals using one or more of the steps described herein, removing the clean well plate(s) from the device, and using the clean well plate(s) in a new experiment/reaction. These steps may be repeated as needed.

Any suitable cleaning fluid or reagent (these terms are used interchangeably herein) may be used in the well plate washing device of embodiments of the invention, such as GrenoClean from Grenova, Inc., ethanol, DI water, bleach, etc. (and combinations thereof). The cleaning fluid or reagent is used to chemically break down and sanitize experiment residues.