The dispensing well plate: a novel device for nanoliter liquid handling in ultra high-throughput screening

A novel method for massive parallel dispensing of liquids in the nanoliter range has been presented. The proposed DWP method has been studied experimentally using prototypes fabricated by different micromachining techniques. Their dispensing performance was successfully characterized by gravimetric and fluorometric experiments. The DWP prototypes were able to deliver fixed volumes between 43 nL and 50 nL, with a CV as low as 1%, when dispensing an array of 24 droplets simultaneously onto a slide and measuring fluorescence with a biochip reader.The proposed DWP method has been proven to be very accurate, scalable, simple, and robust. A reproducibility of the mean dosage volume of better than 3% has been obtained by gravimetric measurements for all prototypes dispensing aqueous solutions or pure DMSO. The DWP technology, therefore, has the potential to speed up the liquid handling in HTS by a factor of 10 to 100 and reduce reagent consumption by a factor of 10 to 20 in the future. The applicability of the DWP method in an HTS laboratory environment has been demonstrated by performing a miniaturized kinase assay with comparable quality to conventional assay volumes. By the demonstrated miniaturization, the reagent consumption could be reduced by a factor of 20.     

Conceptual design for an automated high-throughput magnetic protein complex purification workcell

One of the major challenges facing the emerging field of proteomics research is related to the technical difficulties in analyzing protein structure and function on a genomic scale. The routine purification of protein complexes as a means to investigate protein–protein interaction networks is of particularly high interest because of its significant potential to improve overall understanding of protein function and to improve ongoing drug discovery efforts. Automation of currently practiced laboratory procedures has the potential to markedly improve protein purification throughput, but important technical issues remain to be addressed. This paper investigates key bottlenecks in the automation of standard affinity-based procedures for protein complex purification and introduces a promising conceptual design for an automated workcell that would allow for rapid and efficient magnetic bead-based purification of protein complexes from model organisms suitable for a medium-sized research laboratory setting. The design specifications are based on a modular and flexible design that will permit routine, unattended batch isolation and processing of protein complexes from microbes.     

Nonlinear model predictive control for hydrobatics: Experiments with an underactuated AUV

Hydrobatic autonomous underwater vehicles (AUVs) can be efficient in range and speed, as well as agile in maneuvering. They can be beneficial in scenarios such as obstacle avoidance, inspections, docking, and under-ice operations. However, such AUVs are underactuated systems—this means exploiting the system dynamics is key to achieving elegant hydrobatic maneuvers with minimum controls. This paper explores the use of model predictive control (MPC) techniques to control underactuated AUVs in hydrobatic maneuvers and presents new simulation and experimental results with the small and hydrobatic SAM AUV. Simulations are performed using nonlinear model predictive control (NMPC) on the full AUV system to provide optimal control policies for several hydrobatic maneuvers in Matlab/Simulink. For implementation on AUV hardware in robot operating system, a linear time varying MPC (LTV-MPC) is derived from the nonlinear model to enable real-time control. In simulations, NMPC and LTV-MPC shows promising results to offer much more efficient control strategies than what can be obtained with PID and linear quadratic regulator based controllers in terms of rise-time, overshoot, steady-state error, and robustness. The LTV-MPC shows satisfactory real-time performance in experimental validation. The paper further also demonstrates experimentally that LTV-MPC can be run real-time on the AUV in performing hydrobatic maneouvers.