A current problem for a wide range of chemists is when stirring a solution in the laboratory there is a need to check the properties of the solution and monitor how they change.

In the paper, ‘Monitoring chemistry in situ with the Smart Stirrer —a magnetic stirrer bar with an integrated process monitoring system’ published in the journal ACS Sensors, researchers from the School of Engineering, the Mathematics Institute and WMG at the University of Warwick present their innovative stirrer sensor.

The small device, called “Smart Stirrer”, performed a function of a conventional laboratory stir bar, has an integrated microprocessor and various sensors capable of wireless and autonomous report the conversion of properties of a solution. The advanced sensor stir bar is a capsule shaped magnet encased in plastic.

A beaker filled with a solution is placed on a platform that generates a rotating magnetic field, when the magnetic stirrer is placed in the solution it continuously rotates stirring the liquid.

The Smart Stirrer then monitors:

• Colour
• Transparency
• Conductivity
• Viscosity
• Temperature

Results are sent to a computer over Bluetooth, and any changes notify the user wirelessly. Although the idea of using magnetic stir bar with integrated sensors may not be entirely new, this new affordable, multi-sensor and easy programmable stirrer sensor device is first in its kind.

The concept is valuable to Research and Design laboratories and pharmaceutical and chemistry manufacturing industries because it allows wireless monitoring of several parameters of a chemical reaction simultaneously.

Dr Dmitry Isakov, from WMG at the University who led the study comments:

“We are still continuing research into the stirrer, the next revision of the stirrer sensor that will be smaller size and with a bit more sophisticated sensors. We are collaborating with several chemists from Warwick University. This will help us to understand their needs and help to improve the device.

“The beauty of the Smart Stirrer is that it can be used everywhere, such as a sealed vessels thus minimising the contamination of the reactor. It may give a push to new discoveries as well. It is easy to integrate the stirrer into the labware family and make it “speak” to other lab equipment.”

Samuel Baldwin, from the Mathematics institute at the University of Warwick worked on the smart stirrer during his WMG summer internship, he comments:

“I have found every stage of development of the Smart Stirrer to be very fulfilling, from circuit design, to manufacturing to finally programming. We have leveraged state-of-the-art technology to build a device with very low power consumption, a broad range of sensor capabilities, and high data-throughput over the Bluetooth Low Energy platform.

“The laboratory of the future is that of automation, reproducibility and safety; our all-in-one Smart Stirrer device eliminates the need for a vast array of individual wired sensors whilst maintaining the control and customisability that one would expect from any piece of advanced laboratory equipment. I look forward to seeing the Smart Stirrer solve laboratory problems and help us understand complex reactions.”

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