AND WEIGHING ANALYTIC QUANTITIES OF PARTICULATE SUBSTANCES

BACKGROUND OF THE INVENTION

This invention relates to an automated system and method for handling and weighing analytic quantities of a substance. This invention more specifically relates to a system and method for precisely handling and weighing analytic quantities of substances, particularly including highly sticky viscous materials.

Background and Discussion of the Prior Art

The biochemical and pharmaceutical art desires a system and method for automatically handling and precisely weighing analytic quantities of a substance, particularly particulates. The weighed substances are generally in analytic amounts or quantities for subsequent reaction or processing such as in a biochemical assay or screening. Large numbers of vials containing such precisely weighed amounts of substances need to be handled with speed and accuracy. Often the substances are highly viscous and/or sticky. The present methodologies for handling and weighing such particulates are not entirely satisfactory in that high volume precision handling and weighing of such substances is difficult to achieve.

It is known in the art to provide specially designed and fabricated pipette tips and sampling tools for handling particulates. Such specialized pipette tips are disclosed in EP 05561 95, published, August 25, 1993 to Jensen; and U.S. 5,337,620, granted August 16, 1994 to Kalidini. It is also known in the art to provide a powder-dispensing robot, as disclosed in U.S.

Patent No. 6,674,022 to Fermier et al. for an apparatus and method for transferring and weighing powder materials using pipette tip transfer devices. The Fermier et al. patent discloses a powder-dispensing robot. The robot is preferably a Zymark Prelude multi-purpose workstation re-configured for dry powder handling and weighing. A vacuum flow rate controlled pipette tip is employed to pick-up and transfer the dry powder. The vacuum controlled action is particularly suitable for free-flowing dry powders, but not for viscous, sticky materials.

The art desires a system and method for handling a broad range of substances, particularly including viscous, sticky materials. The art also desires a system and method for precisely handling, transferring, and weighing predetermined analytic quantities of such difficult to handle substances. The art also desires a system and method for high volume precision weighing of substances, particularly including viscous, sticky materials.

It is therefore a principal object of the present invention to provide a system and method for the automated handling of analytic quantities of a broad range of substances.

It is another principal object of the present invention to a system and method for the high volume automated precision weighing of analytic quantities of a broad range of substances.

It is also an object of the present invention to provide a system and method as aforesaid wherein the substance is viscous and/or sticky.

It is still a further object of the present invention to provide a system, and method as aforesaid which automatically determines if a substance supply container or source vial is effectively empty, and automatically removes the deemed empty source vial from ongoing handling and weighing operations.

It is still a further object of the present invention to provide a system and method as aforesaid in which the substance supply container or source vial is automatically diversely manipulated to collect and readily access the substance for removal. It is still a further object of the present invention to provide an automated system as aforesaid which prevents substance cross-contamination.

The aforesaid objects, as well as other objects and advantages, will be manifestly apparent by one of ordinary skill in the art from a reading of the following description and adjoined claims.

SUMMARY OF THE INVENTION

A system and method are provided in which a robot arm having a rotatable joint sequentially, operably, disconnectably engages a first hand for manipulating a substance supply container or source vial, a second hand for manipulating a substance receiving container or destination vial in conjunction with a weigh station, and a third or spinner hand which removably receives a distally disposed elongated flexible member, such as a pipette tip, for removing the substance from the source vial and then depositing the removed substance into the destination vial. The third hand spins and/or vibrates the flexible elongate member or pipette tip in a resultant elliptical path to discharge or deposit an aliquot of the removed substance into the destination vial. This substance removal and deposition is automated and repeated until the desired predetermined analytic quantity of the removed substance is deposited in the destination vial. The actual quantity (i.e., weight) of the removed substance in the destination viai is recorded and may be later referenced for calculating concentration, another measurement, or physical characteristic when the removed substance is dissolved in solution, utilized in a chemical reaction, or otherwise processed.

The present invention provides for automated screw-cap removal from the source vial, and then tilting and rotating of the source vial in a specially designed tilting and rotating

mechanism. The rotated and tilted source vial causes the substance to be collected at the bottom corner of the source vial for better access to the substance. The pipette tip is automatically inserted into the tilted source vial to engage the substance gathered at the bottom corner of the source vial. The pipette tip is then spun at high speed while in contact with steel wool or other substances to generate electrostatic charges on the outside surface of the pipette tip. The electrostatically charged pipette tip will pick up an aliquot of the engaged substance from the source vial and then transferred to the destination vial, whereat the flexible pipette tip is spun and vibrated by the third hand, in preferably a resultant elliptical path), whereby an amount of substance is dislodged from the outside surface and within the pipette tip, and by gravity deposited into the destination vial. The tared destination vial, with the deposited substance, is weighed at the weigh station. The foregoing procedure is repeated until the prescribed weight is obtained. In the event the prescribed weight is not obtained after a programmed number of repeated substance removal and deposit attempts, the source vial is determined or deemed to be empty. The deemed empty source vial is then automatically removed from the system. The foregoing operation may be automatically repeated with another source vial containing the same substance. After each weighing sequence, the used pipette tip containing residual substance is discharged into a waste receptacle to avoid cross contamination. The destination vial with the accurately weighed amount of substance is returned to a specific programmed position in the destination vial tray (e.g., its initial position). In this manner of operation, the specific substance in the prescribed amount is in a programmed position for subsequent reaction and processing, such as a bioassay.

The source vial tilting and rotating mechanism and the used pipette tip discharge mechanism are separate specific novel constructions of the present invention. The source vial is gripped and tilted to a prescribed angle and rotated. The source vial is seated above a leaf spring. The pipette tip, in repeated, programmed, up and down strokes, contactingly engages the substance. The pipette tip, when contactingly engaging the substance in the source vial, may unduly flex. The leaf spring takes up the reaction force exerted by the pipette tip on the substance to prevent undue flexure, bending or breaking of the pipette tip. The tilting and rotating mechanism and leaf spring cooperate to permit rapid, efficient collection and removal of the substance. This is particularly so for substances that are highly viscous and sticky.

The present system provides a high-speed automated means for handling and weighing analytic quantities of a broad range of substances, particularly including viscous, sticky particulates.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG 1 is a schematic perspective view of the automated handling and weighing system of the present invention;

FIG 2 is a top plan view of the automated system of the present invention; FIG. 3A in an enlarged plan view of the source vial cap removal and source vial tilting and rotating mechanism of the present invention;

FIG. 3B is a side elevational view of the source vial cap removal and source vial tilting and rotating mechanism as shown in FIG. 3A;

FIG. 3C is a schematic illustration of the open source vial in tilted disposition for accumulation of the substance in preparation for removal by the pipette tip; FIG. 4A is an enlarged top plan view of the sample weighing station; FIG. 4B is a front elevational view of the weighing station as shown in FIG. 4A; FIG. 5A is an enlarged top plan view of the used pipette tip discharge mechanism; FIG. 5B is a front elevational view of the used pipette tip discharge mechanism as shown in FIG. 5A;

FIG. 6 is a schematic diagram of the step-wise operation of the present system; and FIG. 7 is a greatly enlarged side elevational view of the spinning hand with the engaged pipette tip undergoing spinning to dislodge particulates of the substance from within and on the outside surface of the pipette tip.

DESCRIPTION OF THE INVENTION

The terms "first," "second," and "third" are used herein principally to identify and distinguish one robot hand or hand means from another, and are not intended necessarily to signify the order or sequence of their use.

Referring to FIGS. 1 , 2, 3,4, 5a, 5b, and 7, there is shown an automated system for handling and weighing analytic quantities of substances according to the present invention.

The automated system includes a programmable robot 11 having an arm 12 and a joint 13.

Arm 12 has diverse angular degrees of motion as shown by arrows A, B, C, Dl and E (FIG. 1 ). Robot 11 is fixedly positioned and mounted on stationary base or platform 10.

A source vial plate or tray 15 is specifically positioned and removably mounted on platform 10. Tray 15 comprises an x-y grid of source vial receiving positions or holes 151 that are sized for slidably receiving respective source vials 20. Source vials 20 are capped by removable screw caps 21 , and are of well-known conventional size and construction (e.g., 5 ml (1 DRAM) vials). Alternatively, a source vial can be any flat or conical bottom vials that can be fitted between 323 and 325 (see below) can also be used. Each source vial 20 contains a compound or substance. Each source vial 20 may contain the same or a different substance.

Each source vial 20 preferably includes an identifier, such as a barcode (not shown), for automated identification of the substance therein. Each source vial 20 is positioned in source vial tray 15 in a specific programmed hole 151 in the x-y grid. Source vial tray 15, in this specific embodiment, has ninety-six receiving holes 151. This translates into ninety-six possible weighing sequences. A spreadsheet or database for each weighing operation records the identity of the respective source vial 20, the tare weight of the respective destination vial 25 (described hereinbelow), and the weight of the tared destination vial 25 with the compound or substance therein. Optionally, tray 15 may hold at least one tube 22 that contains steel wool or a similarly abrasive substance, and that is adapted to score or cut the exterior surface and create electrostatic charges on the outside surface of an elongated member or pipette tip inserted into tube 22. Tube 22 preferably comprises a cap with an aperture sized to allow insertion of an elongated member or pipette tip, while preventing escape of the abrasive substance held therein. A preferred steel wool is super-fine grade (#0000), but other grades (e.g. #00, #0, #l, #2, #3) can be used as well. A destination vial plate or tray 16 is specifically positioned and removably mounted on platform 10. Destination vial tray 16 has an x-y grid of holes or programmed positions 161. Holes 161 are sized for slidably holding destination vials 25. Destination vials 25 preferably do not have caps. Each destination vial 25 is empty when initially loaded into tray 16. Destination vials 25 are sized for receiving analytic quantities of the substance or substances stored in source vials 20. In this specific embodiment, destination vial tray 16 holds ninety-six conventional 1 DRAM vials. Destination vials 25 are of generally conventional design and are preferably commercially available (e.g. Denville Scientific catalog # B1251).

A pipette tip tray 17 is specifically positioned and removably mounted on platform 10. Pipette tip tray 17 has an x-y grid of holes or programmed positions 171 for receiving pipette tips 29. As best shown in FIG. 7, each pipette tip 29 has a proximate end 291 , an elongated tubular body 292, a frusto-conical distal end 293, and a distal end open tip 294. In this specific embodiment, pipette tip tray or plate 17 holds ninety six pipette tips. Pipette tips 29 may be any thin flexible pipette tip of conventional design and construction. A small thin flexible plastic pipette tip having a tubular body and a frusto-conical tip is one preferred construction. A broad range of pipette tips and thin elongate members are within the contemplation of the present invention.

Referring to FIGS. 1 and 2, there is shown a first hand means or hand 80, a second hand means or hand 90, and a third hand means or hand 100. Hands 80,90, and 100 are seated or removably stowed on respective specifically contoured bases 85, 95, and 105. Each base 85, 95, and 105 is specifically positioned and fixedly mounted on platform 10.

Hands 80, 90, and 100 are formed with proximate end respective connectors 82, 92, and 102 for disconnectable connection to robot arm joint 13. Hands 80, 90, and 100 are

formed at their distal ends with respective means for carrying out source vial, pipette tip, or destination vial functions. First hand 80 preferably includes relatively large or long pins with which to grip source vials 20 and source vial caps 21. Second hand 90 preferably includes relatively small or short pins with which to manipulate destination vials 25. Third hand 100 is specially designed and adapted to hold a pipette tip 29, as well as rotate and/or vibrate the same, as will be more fully explained hereinafter.

Referring again specifically to FIGS. 1 , 2, 3A, 36, and 3C, there is shown a source vial holding (i.e., gripping), rotating, and tilting mechanism or assembly 30. Assembly 30 includes, in general terms, a base assembly 31, a source vial gripping and tilting mechanism 32, and a source vial rotating assembly 35. Base assembly 31 is fixedly disposed on platform 10.

Source vial gripping and tilting mechanism 32 includes a well or seat 321 for slidably receiving a source vial 20. Source vial gripping and tilting mechanism 32 tilts a gripped source vial 20 to a specifically predetermined angle D (Fig. 3C). Source vial 20 is disposed in receiving seat or well 321 between opposed semi-circular grippers 323 and 325. A leaf spring 329 is operably disposed below well 321 and above base 31. In this manner of construction, source vial 20 is gripped, and first hand 80 rotates and removes or unscrews cap 21. After the removal of screw cap 21 by the rotation of hand 30, source vial 20 is tilted by source vial gripping and tilting mechanism 32 to the desired predetermined angle D. As a result of the foregoing operation, the substance in source vial 20 is collected at the angled bottom portion of vial 20 in preparation for removal by pipette tip 29, as best shown in FIG. 3C.

The gripped and tilted source vial 20 may be rotated by source vial rotating assembly 35 (Fig. 38). Source vial rotating assembly 35 includes a drive motor 351 (i.e., a step drive motor), a drive wheel 352, and a friction wheel 353. Drive wheel 352 and friction wheel 353 are operably frictionally connected by an endless belt 355. In this manner of construction, drive motor 351 turns drive wheel 352 that drives endless belt 355, which in turn drives or rotates friction wheel 353. Friction wheel 353 includes an elastomeric or rubber peripheral surface 354 for resiliently frictionally engaging the outside or periphery side of a source vial 20. The rotation of friction wheel 353 causes source vial 20 to rotate in seat 321. A spring- loaded slave or bracing wheel 327 is mounted in opposed disposition to friction wheel 353. Bracing wheel 327 resiliently bracingly engages source vial 20. Bracing wheel 327 rotates with the rotation of source vial 20.

Referring to FIGS. 1, 2, 4A, and 4B, there is shown weigh station 40. Weigh station 40 includes an analytic scale or weighing balance 41 for holding an initially empty destination vial 25 to tare same, and for subsequently holding that destination vial 25 with deposited substance 201 therein to weigh same. Balance 41 may be of conventional design and commercially available (e.g. Mettler MT5 microbalance). Weigh station 40 includes a cover

means 42 for isolating a destination vial 25 to ensure accurate weighing, and base 46 assembly that is positioned and removably mounted on platform. Weigh station 40 includes resilient mounts 43 to isolate balance 41 and insure accurate weighing, as is well known in the analytic weighing art. Balance 41 is of generally conventional construction. Furthermore, a static elimination device of well known construction (not shown) may be provided to insure accuracy in weighing.

Referring to FIGS. 1, 2, 5A, and 5B, there is shown used pipette tip discharge station 50. Pipette tip discharge station 50 includes (i) housing 51, (ii) waste receptacle 52 removably positioned within housing 51, (iii) cover plate 53 having vertical through hole 532, (iv) pipette tip holding mechanism 54 that includes annular member 542, which defines vertical through- hole 543 and horizontal slot 545, and (v) strike plate assembly 55. Strike plate assembly 55 includes, in operable combination, (i) plate 551 having strike plate edge face 552, (ii) pivot 553, (iii) drive air cylinder 554, (iv) reciprocal piston 555, and (v) connection 556. When drive 554 is actuated, reciprocating piston 555 moves in the direction of arrow F. Plate 551 rotates a few degrees through pivot 553, and strike plate edge face 552 moves in turn through horizontal slot 545 and partially across vertical through-hole 543, as shown by arrow G. In this manner of construction, when third hand 100 positions a used pipette tip 29 into through-hole 543, drive cylinder 554 may be actuated to cause strike plate edge face 552 to transversely engage elongated tubular body 292 of used pipette tip 29. Thereby, used pipette tip is reieasably firmly held in pipette tip holding mechanism 54. Subsequent movement of third hand 100 up and away from station 50 disengages used pipette tip 29 from third hand 100. After third hand 100 has been disengaged from used pipette tip 29 and in preparation to receive the next used pipette tip, piston 555 reciprocates (arrow H) and returns strike plate 551 to its initial position (FIGS. 5A and 5B), in turn causing used pipette tip 29 in pipette tip holding mechanism 54 to fall freely downwardly and out of through-hole 543 and through-hole 531 to be collected in waste receptacle 52. The accumulated used pipette tips 29 are retained and isolated in housing 51 , thereby eliminating the prospect of cross-contamination.

Referring specifically to FIG. 6, there is shown the sequence operations of the aforesaid construction. It is to be noted that the programmable means actuates each operation in the sequence described in FIG. 6. The sequence of operations begins at the uppermost listed operation and proceeds sequentially to the lowermost listed operation. The sequence of operations is repeated automatically. There is essentially no human hand intervention in these fully automated operations. The only human intervention is to (i) place or replenish the appropriate source vials 20 in source vial tray 15 and/or secure a pre-filled source vial tray 15 to platform 10, (ii) place or replenish destination vials 25 in destination vial tray 16 and/or secure a pre-filled tray 16 to platform 10, (iii) place or replenish pipette tips 29

in pipette tip tray 17 and/or secure a pre-filled pipette tip tray 17 to platform 10, and/or (iv) empty waste receptacle 52 containing used pipette tips 29.

Robot arm 12 moves into position to engage robot arm joint 13 with first hand 80. Robot arm 12 removes first hand 80 from first hand storage seat 85. Using first hand 80, capped source vial 20 is picked up and placed between opposed semi-circular grip members or grippers 323 and 325. Gripper 325 is then retractably moved inwardly toward gripper 323 to grip or clamp source vial 20. First hand 80 rotates to remove or unscrew cap 21. Specifically, first hand 80 releases source vial 20, initially rotates a full clockwise turn, re-grips cap 21, and turns counter-clockwise about 300". First hand 80 then releases cap 21 , and repeats the foregoing sequence of rotations. Source vial 20 requires about 540" degrees of rotation (about one and one-half counter-clockwise turns) to ensure that the threads of source vial 20 are fully disengaged from cap 21. At this point in the process, cap 21 is free from source vial 20, and first hand 80 with unscrewed cap 21 is returned to first hand seat '85 by robot arm 12. First hand 80 is spring-loaded so that, when disconnected from arm joint 13, there is sufficient pressure on cap 21 to hold it in place when hand 80 is disconnected from arm joint 13. Gap 21 stays in first hand 80 during the remainder of the weighing sequence to avoid cross contamination. Once cap 21 is removed from source vial 20, source vial 20 does not need to be tightly gripped again until cap 21 is to be re-threaded onto source vial 20, and (as described hereinbelow) source vial 20 must be free to rotate in seat 321. Thus, at any suitable time after cap 21 is removed, grip member 325 is retracted so that members 323 and 325 encircled, but do not grip, source vial 20.

After uncapping source vial 20 and replacing first hand 80 in first hand storage seat 85, robot arm 12 moves to a position adjacent to second hand storage seat 95 and picks up second hand 90. Using second hand 90, a destination vial 25 is picked up from tray 16 and placed in weight station 40. To avoid crushing destination vial 25, the air pressure is reduced by a regulator and pneumatic switching system (not shown) to reduce the pressure applied to destination vial 25 by second hand 90. Robot arm 12 moves to a position over weigh station 40, and waits for cover 42 to be opened. Once cover 42 is opened, destination vial 25 is inserted or dropped into destination vial holder 45. At approximately the same time, robot arm 12 returns second hand 90 to second hand base 95, and cover 42 is closed.

Robot arm 12 moves to a position over third (spinner) hand base 105, and then moves downwardly and picks up third hand 100. Robot arm 12 then moves third hand 100 to the pipette tip tray 17 and engages third hand 100 with a pipette tip 20 from a programmed position 171. Third hand 100 with pipette tip 29 moves to a position over source vial 20 secured between semi-circular grippers 323 and 325. About the time that robot arm 12 and third hand 100 and pipette tip 29 arrive over source vial 20, robot 11 sends a signal to weigh

station 40 to perform a tare with destination vial 25 resting on balance 41. If a tare greater than 0.01 mg is detected by robot 11, another tare is undertaken.

Preferably, before pipette tip 29 moves to a position over source vial 20, pipette tip 29 may be inserted into tube 22 which contains steel wool. It has been discovered that, by scoring or cutting the exterior surface of pipette tip 29 against the steel wool by spinning the pipetted tip at high speed (e.g. 1000 rpm by the motor mounted in the third hand 100) for a short duration (0.1 second), a static charge is developed on the scored exterior surface. The static charge is useful for statically attracting particles 201 to the scored exterior surface, whereby particles from source vial 20 can be easily and quickly removed by inserting the statically charged pipette tip 29 into source vial 20 and in contact with particles 201 therein, rotating the source vial 20 against the statically charged pipette tip 29 to attract particles 201 thereto, and removing the statically charged pipette tip 29 carrying the adhered particles 201 out of source vial 20 for disposition in destination vial 25.

Robot 11 signals source vial tilting mechanism 32 to tilt at a predetermined angle to facilitate access to compound 201. Tilting mechanism 52 tilts the gripped source vial 17 to cause the substance to dislodge from the sides of the source vial and gravitate to the corner and collect at the bottom of source vial 17 for ready access for removal. While tilted, source vial 20 is in contact with friction wheel 353. At any appropriate time, drive motor 351 may be actuated to rotate drive wheel 351 , drive belt 355, and, in turn, friction wheel 353. Friction wheel 353 causes the tilted source vial 20 to rotate in seat 321. In the event compound 201 is accumulated on an inside surface of source vial 20, the tilting and rotation of source vial 20 causes compound 201 to dislodge from the inside surface and accumulate at a bottom corner of source vial 20 to facilitate access for removal.

Robot 11 moves pipette tip 29 into source vial 20 in contact with substance 201. When pipette tip 29 has been preferably scored and statically charged, the source vial 20 was rotated by the friction wheel 353 four times to expose the entire exterior surface of pipette tip 29 to the particles of substance 201. If pipette tip 29 has an appropriately sized open tip 294, pipette tip 29 may be optionally moved vertically in-and-out of substance 201 about four times to force compound 201 into the open tip 294 of pipette tip 29. After the rotation and/or vertical insertion into source vial 20, robot 11 moves pipette tip 29 over weigh station 40, draft shield 42 opens, and robot arm 12 is positioned over pre-positioned destination vial 25. Tip 294 is moved down and into destination vial 25. Third hand 100 spins pipette tip 29, as previously and further described.

■ Referring specifically to FIG. 7, there is illustrated a detail view of third hand 100 in operable position inside destination vial 25. Third hand 100 engages proximate end 291 of pipette tip 29. Pipette tip distal end 294 is positioned adjacent to the open end of destination vial 25. When so positioned, hand 100 rotates and/or vibrates pipette tip 29 as shown

generally by arrow I. Pipette tip 29, by virtue of its flexible construction, rotates in a resultant generally elliptical path or motion as shown by arrow J. In this manner of operation, the portions of compound or substance 201 , which are held in and on the pipette tip frusto-conical distal portion 293 by virtue of their sticky character, are disengaged or discharged generally downwardly (arrow K) into destination vial 25 by virtue of gravity and the elliptical motion of pipette tip 29.

Referring again to FIG. 6, robot arm 12 is moved up and away from weigh station 40 and/or back to and over source vial 20. Weighing station shield door 42 is closed, and a signal from the programmed robot initiates a weighing cycle in balance 41. If the weight of compound 201 in destination vial 25 is less than 0.3 mg, robot arm 12 initiates another cycle to pick-up an additional aliquot or amount of compound 201 from source vial 20, and the additional aliquot or amount of compound 201 is deposited into destination vial 25. Compound 201 will continue to be picked-up, dispensed, and weighed until at least 0.3 mg or the desired weight is measured in destination vial 25. Once this occurs, third (spinner) hand 100 moves to pipette tip discharge station 50 where used pipette tip 29 is stripped from third hand 100. Third hand 100 is then replaced in its seat 105.

Robot arm 12 picks up second hand 90 from second hand base 95. It then moves to a position over weigh station 40, draft shield door 42 opens and robot arm 12 moves downwardly to a position where second hand 90 it is able to grip destination vial 25. Second hand 90 grips vial 25, moves up, draft shield door 42 then closes, and robot arm 12 moves over tray 16. Second hand 90 returns the filled destination vial 25 to a specific receiving hole 161 , which is preferably the same receiving hole 161 from which destination vial 25 was initially removed. Second hand 90 is then returned to second hand seat 95. Robot arm 12 then moves to its initial start position. Robot arm 12 then moves from its initial position to a position over first hand seat 85 and picks up first hand 80 with the retained source vial cap 21. The robot 11 moves to source vial holding, rotating, and tilting assembly 30 where the uncapped source vial 20 remains secured between grippers 323 and 325. Grippers 323 and 325 retract to grip source vial 20. First hand 80 moves to full counter clockwise rotation, and then moves down to source vial 20 to a position where cap 21 engages the top of vial 20. First hand 80 rotates clockwise 300" degrees, releases, and re-turns 300" to re-screw cap 21 fully on vial 20. First hand 80 re-grips cap 21 and completes another 300" turn. When cap 21 becomes fully re-screwed or tightened, re-capped vial 20 will be released from grippers 323 and 325 in seat 321. First hand 80 retains its grip on the recapped source vial 20. Robot arm 12 lifts the recapped vial 20 and moves it to source vial tray 15 in the same programmed position or hole 151 from which it was initially lifted. Robot arm 12 moves downwardly and first hand 80 releases source vial 20. At this time the system is ready for another cycle.

The interface between the Mitsubishi robot controller and the electronic and pneumatic controls is accomplished by using the 32-line 110 interface provided in the controller. The 16 110 output lines are connected to two eight section solid state relay boards that convert 5 volt logic signals to 24 volt drive signals. These signals are connected to the 24-volt solenoids that control the pneumatic valves for the grippers. The motor hand 100 with the spinner which requires 24 volts, is also controlled by these relays. The robot of the present system is preferably a Mistubishi RV-2-A robot art. The programming of the robot arm is by means well known in the art and by a programmer of conventional skill in the art.

The following Table 1 is a step-by-step example of each sequential elapsed operation and the elapsed time from operation to operation.

TABLE 1

It is within the contemplation of the present invention to handle and weigh a broad range of substances having diverse physical characteristics, particularly including sticky, viscous, cementacious materials. Indeed, the present invention has been successfully tested using for example, glycerol, honey and molasses.

While the foregoing describes a pipette tip as the means for the substance removal, it is within the contemplation of the present invention to use any elongate member, including flexible rods or tubes. Where a pipette tip or similarly tubular member is used, it is also within the contemplation of the present invention to provide a filter within the tubular body to prevent

upward migration of the substance to the hand means to avoid cross-contamination between samples. The use of a broad range of elongate members for a broad range of substances is a particular commercial advantage of the present invention.

It is to be understood that the embodiments described in this specification are merely illustrative of the invention and that many variations may be devised by those skilled in the art without departing from the scope and spirit of the invention. It is therefore intended that such variations be included within the scope of the following claims and their equivalents.