Final Design

High throughput screening has become a popular method of biological assay for biologists and chemists as it only requires a very small and dilute volume of chemicals to analyze. 

This small volume, usually between 0.5mL and 20mL, must be thoroughly mixed before screening. However, existing magnetic laboratory stirrers typically only have a minimum stirring volume of 50mL. Further, they are often wired and the device power cables cause additional clutter in fume hoods where biologists and chemists typically conduct their experiments. 

The following magnetic stirrer prototypes are a way to enter this untapped market.

Functional Requirements

• 5 mm maximum thickness 

• 4+ stirring positions 

• Battery powered 

• Wireless control 

• 1500+ maximum stirring speed

Overview of Modules

Conclusions

Individually, each module nearly met the functional requirements but had its own shortcomings. Together they achieved all functional requirements.

The battery powered module is promising since it is a very portable, self-contained unit with the potential of being completely sealed. The discrepancy in the stirring capabilities of the two modules highlights how important magnetic field strength is in reliably stirring solutions since the wired module was powered at 12V while the battery powered module only at 5V.

In order for a single module to meet all functional requirement, these modules must be optimized. A very thin battery must be used to keep module thickness down and highly permeable magnetic core materials must be used to produce a strong enough field for the low currents sourced by a battery. Additionally, a controller must be found or manufactured such that its own current draw does not dramatically impact battery life of the module.