Laboratory robotization

It is the first stage of laboratory analytical methodologies which poses the greatest problems for automation (see Chapter 2). Operations such as weighing, dissolution, grinding and centrifugation are difficult to incorporate on-line in automatic analysers (whether batch or continuous). It is therefore here that robotic systems cover a field inaccessible to the remainder of automatic methodologies. 

This first stage is as important as or even more so than the other two inasmuch as (a) they are a major source of a variety of errors —some of them so large as to decisively influence the final result—, (b) they are time-consuming, (c) they are complex and expensive and (d) the system is subject to human contamination, which is a high risk in trace analysis, for instance. 

Laboratory robotization Is chiefly aimed to the first few stages of the analytical process —hence its relevance to analytical procedures involving long, multi-stage preliminary operations. 

There are two basic options for incorporation of robots into laboratory 

There are three types of connection in a robotic station (a) human, between the computer and the operator (b) computerized, between the microprocessor and the robot and the different apparatus and instruments and (c) mechanical, between the robot and its environment. 

---

The use of "fixed" automation, automation designed to perform a specific task, is already widespread ia the analytical laboratory as exemplified by autosamplers and microprocessors for sample processiag and instmment control (see also Automated instrumentation) (1). The laboratory robot origiaated ia devices coastmcted to perform specific and generally repetitive mechanical tasks ia the laboratory. Examples of automatioa employing robotics iaclude automatic titrators, sample preparatioa devices, and autoanalyzers. These devices have a place within the quality control (qv) laboratory, because they can be optimized for a specific repetitive task. AppHcation of fixed automation within the analytical research function, however, is limited. These devices can only perform the specific tasks for which they were designed (2). 

See Process control. Robots in the scientific laboratory, Robots, processing. 

The labor-intensive nature of polymer tensile and flexure tests makes them logical candidates for automation. We have developed a fully automated instrument for performing these tests on rigid materials. The instrument is comprised of an Instron universal tester, a Zymark laboratory robot, a Digital Equipment Corporation minicomputer, and custom-made accessories to manipulate the specimens and measure their dimensions automatically. Our system allows us to determine the tensile or flexural properties of over one hundred specimens without human intervention, and it has significantly improved the productivity of our laboratory. This paper describes the structure and performance of our system, and it compares the relative costs of manual versus automated testing. 

Figure 1. Overall instrument layout showing (A) Instron 1125 universal tester (B) Zymark laboratory robots (C) Specimen bar magazine (D) Specimen bar measuring device.

A comprehensive listing of all the vendors that offer HTS instrumentation and platforms is beyond the scope of this chapter, but most vendors maintain informative websites and there are three professional organizations that disseminate useful information about automation platforms for HTS on the world wide web, the Society for Biomolecular Sciences (www.sbsonline.com), the Association for Laboratory Automation (www.labautomation.org), and the Laboratory Robotics Interest Group (www.lab-robotics.org). The latter maintains an online forum where vendors and experienced users often provide immediate and useful guidance. 

The most recent extension of instrument automation has come with the availability of practical laboratory robotics systems. These systems can be as easy to implement as the personal computer data system and extend automation beyond control, data collection and... 

The Automation of Repetitive Analysis. Constant Monitoring and on Line Analysis. Laboratory Robotics. 

Early laboratory robots were unreliable, but today, these systems perform quite well. Today s robots simply move plates from one robot-friendly position to another, such as the entrance pad of a plate reader. These simplified movements combined with the low weight of a plate allow engineering to simplify the robot designs. As seen in industrial application of robots, robots that are defined and used for a specific application will work day in and day out quite well. It is always best to keep the automation as simple as possible to get the highest level of performance. This is usually accomplished by minimizing the number of moveable parts associated with the automation. Stackers have also become more reliable. This was due, in part, to the standardization of the microplate by an effort of the Society for Biomolecular Screening (Danbury, CT, U.S.A.) in association with the American National Standards Institute (ANSI, Washington, DC, U.S.A.), but also due to the use of simpler stacker mechanisms. Today, there are many choices for devices, workstations, and fully automated systems. The selection as to which automated devices to purchase for HTS should be driven by a clear set of specifications that define the use of the automation. The choices can be expensive, and therefore, replacement may not be possible, so it is important to choose well. 

The first commercial laboratory robot, the Zymate Laboratory Automation System (Fig. 6.1), was introduced by Zymark Corporation (ffopkinton, Massachusetts, USA) in 1982. Subsequently, some Hght industrial robots have been adapted for laboratory use, and other systems have been introduced. Basic aspects of laboratory robots have been reviewed by Dessy [6, 7], Kenig and Rudnic [8], Isenhour [9] and Lochmuller et al. [10]. More recently. Hawk and Kingston [11] have pubhshed a very comprehensive review with particular regard to trace analysis. 

Fig. 6.1 The first Zymark laboratory robot. Reproduced with permission of Z/mark Corporation.

In contrast to a typical industrial robot, the laboratory robot must be flexible and user-programmable. Many laboratory robots incorporate tactile sensing and other verification methods. However, vision capabilities are virtually nonexistent at this time. Laboratory robots range in price from 25,000- 100,000 with typical system prices averaging 40, 000- S0,000. 

Staff become bored performing repetitive tasks, whereas a reliable laboratory robot will perform procedures uniformly, eliminating human error. Automation permits the frequent use of replicates, standards and controls to verify precision, so the analyst and customer can have complete confidence in the results. Taylor et al. [14] have suggested that the number of blind duplicates sent to control laboratories by operating staff can be as high as 70% of total work load. Reliability and traceability are important benefits of... 

A laboratory robot can operate unattended for 24 hours a day, releasing skilled technicians and scientists for more important and challenging work. Process workers can often be trained to bring the samples to the robot for analysis on a static mode operation. This provides valuable results with a fast timescale. 

Staff have time to develop new shills and assume greater responsibility by delegating boring work to the laboratory robot. These new career opportunities can reduce personnel turnover and retraining costs. 

Laboratory procedures can require the use of potentially hazardous materials. Laboratory robots can minimize human exposure to hazards. Conversely, human contamination of biologically sensitive materials can also be minimized by laboratory robots. 

Unattended operation of the laboratory robot extends the working day and permits faster sample turnaround. In a manufacturing/quality control environment, faster release of product for shipment can greatly reduce inventory costs. 

In addition to improved productivity, quahty of data is a key criterion on which many laboratory robotic appHcations are judged. Automated methods are generally vahdated by verifying that individual workstations are functioning properly, and then comparing the results of the totally automated procedure to those obtained manually. 

Both microwave closed-vessel dissolution and laboratory robotics are relatively new to the analytical laboratory. However, it is this marriage of new methods which provides useful combinations of flexible laboratory automation to meet a variety of individualized needs. Because of the large number of biological samples which are prepared for analysis each day, it is reasonable to assume that this type of innovative automation wiU be of great benefit. It should be evaluated for its ability to improve the preparation technology for trace element analysis of biological materials. 

The system is based on an XP Zymate laboratory robot controlled with a 10 slot System V controller using software version XP VI.S2. The system incorporates commerdaUy available hardware, as well as custom hardware. A schematic diagram of the system is shown in Fig. 6.11. The robotic arm and the peripheral laboratory stations that the robotic arm interacts with to perform the appHcation are positioned in a circular configuration. The GC/MS is located adjacent to the bench top, such that the injection valve is close to the sipper station. Peripheral items of hardware with which the robotic arm does not directly interact with are outside the working envelope. 

Hawk, G.L. and Kingston, H.M., Laboratory robotics and trace analysis in Quantitative Trace Analysis Biological Materials, Edited by McKenzie, H.A. and Smythe, L.E., Elsevier, Amsterdam, 1988. 

C.H. Lochmuller, K.R. Lung and K.R. Cousins, Applications of optimization strategies in the design of intelligent laboratory robotic procedures. Analytical Letters, 18 (A4) (1985) 467. 

---