An automated microscale chemistry workstation capable of parallel, adaptive experimentation

Abstract

We have designed and constructed a 3rd-generation chemistry workstation and accompanying software for automated experimentation in relatively clean domains of chemistry. The workstation is designed for flexible, high-throughput, microscale chemistry and includes a reaction station with 60 reaction vessels. The experiment manager software includes a large number of features to facilitate experiment planning and implementation. The significant advances in software from the 2nd-generation system include the following: (1) Five experiment-planning modules have been incorporated to match different types of scientific experimentation, including open-loop and closed-loop experiments. The five modules enable plans to be composed for general-purpose (GP), decision-tree (DT), factorial design (FD), composite modified Simplex (CMS) and multidirectional search (MDS) experiments. (2) Parallel experimentation and adaptive experimentation have been blended so that some decision-making can be done using objective functions or early-termination functions while multiple experiments are in progress. Some planning modules (CMS, MDS and DT) can cause new experiments to be spawned based on the chemistry data obtained. (3) Decision-making can involve the local course of individual experiments and/or the global course of sets of experiments. (4) Resource management features provide the capability to look-ahead at experiments in queue, assess resource (chemicals, containers) availability and designate suitability for implementation. (5) Intelligent reagent-handling features support the autodilution of reagents, autoselection of appropriate stock solutions, autoassignment of containers and control over reaction volumes. (6) Opportunistic rescheduling features have been provided so that pending experiments can be advanced in queue whenever possible, leading to compressed experimental timeframes. (7) Templates composed for FD, CMS and MDS experiments can be stored and reused with modifications as required for specific experiments. (8) The scheduling module contains both a rigid scheduler and a flexible scheduler. (9) The software is modular and runs under Windows 95. This workstation is especially designed for fundamental investigations of chemical reactions and optimization of experimental reaction conditions.