Mar 19, 2013
Air displacement pipettor provides the key to automated sonochemical synthesis of nanoparticles
Sonochemical synthesis – chemistry driven by ultrasound waves – relies on high intensity sound waves, which are only present near a powerful sonic probe. This makes it difficult to perform large-scale reactions and, as a result, chemists are usually forced to perform labor-intensive batch procedures consisting of numerous small syntheses. To automate these procedures – and decrease labor costs significantly – Go2 Technologies has developed the RADS robotic synthesis machine. Kent Walker, Partner/Owner at Go2 Technologies, explained: "The University of Dayton Research Institute and the Air Force Research Laboratory at WrightPatterson Air Force Base, Ohio, were creating air-stable organically-capped aluminium nanoparticles for the production of hydrogen gas from water, which involved manually pipetting three different materials – alane, titanium isopropoxide, and oleic acid – inside a glovebox. This is a very labor-intensive procedure for a single operator, and we were approached to develop an automated method that could robotically dispense, mix, sonicate and verify, essentially to produce a robotic synthesis machine to automate the manual pipetting and dispensing stages within the enclosure."
"The really big challenge of the whole process was liquid dispensing; we needed something compact and lightweight that could cover a large range of volumes, from 15 µl to 10 ml. Some of the chemicals used are pretty harsh on plastics, and pumping these materials through a mechanical piece of equipment was causing them to degrade and break down quickly. This was where the Cavro Air displacement pipettor (ADP) really came into play. We looked at standard dispensing-type pumping systems but, typically, these wanted to bring the liquids into the device. The nature of the liquids used meant that we needed to find a non-contact mechanism for dispensing and pumping, with tips that were either disposable, or could be removed and replaced during the process. Accurate, reliable dispensing of liquid volumes was also vital."
"As well as implementing the robotic solution, we had to develop a custom airtight chamber that could be purged with nitrogen. After talking to several vendors about the inner chamber we realized that these products were so standardized that they really didn’t fit our solution, and so we designed and built the purge box ourselves. This stainless steel enclosure was specifically sized to house all the equipment required, including the vertical articulating arm, the Cavro ADP, and the reagents, vials and the trays. We had to allow sufficient space for the robotic arm to operate – pipetting with the Cavro ADP, capping and uncapping vials and moving them to a sonic probe – and to accommodate any cables."
"We can now perform batch processing of samples by placing them in individual vials inside the glovebox, and process an entire grid of these vials in one run. A batch of up to 56 vials can be processed, with each one taking around 20 minutes to complete."
Source: GO2 Technologies