New calibration technique enhances accuracy of force measurements in microfluidic environments

Aerospace Information Research Institute, Chinese Academy of SciencesMar 15 2024

A study introduces a novel method for calibrating the spring constant of FluidFM micropipette cantilevers, crucial for the accurate measurement of forces in microfluidic environments. This method addresses the limitations of current calibration techniques, offering a significant advancement in the field of force microscopy.

Fluidic force microscopy (FluidFM) combines the sensitivity of atomic force microscopy with microfluidics' capabilities, necessitating precise calibration of its cantilevers for reliable data. Traditional methods, however, struggle with the unique internal structure of FluidFM cantilevers, leading to inaccuracies.

A recent study (https://doi.org/10.1038/s41378-023-00629-6) published on February 18, 2024, in the journal Microsystems & Nanoengineering, researchers unveiled an innovative calibration technique for FluidFM micropipette cantilevers, pivotal for exact force measurements in microfluidic environments.

The FluidFM is a tiny tool used in microscopic environments to measure forces with high precision. Unlike traditional methods that often fall short due to the complex inner structure of FluidFM cantilevers, this new approach leverages the cantilever's resonance frequencies in both air and liquid environments. By focusing on these frequencies, the method circumvents the common pitfalls of the widely-used Sader method, which can introduce errors due to its reliance on geometric and fluidic assumptions that don't hold up well for FluidFM's unique cantilever designs. This innovative calibration technique was meticulously tested and validated on data obtained by the HUN-REN Nanobiosensorics Lab, Cytosurge, Nanosurf and Bruker, showing that it not only provides more accurate measurements but also simplifies the calibration process by reducing the effects of noise and eliminating the need for intricate experimental setups.

Our method simplifies the calibration process, significantly reducing the influence of noise and eliminating the need for complex measurements, marking a significant step forward in the practical application of FluidFM technologies."

Dr. Attila Bonyár, study's lead author

The new calibration method promises enhanced accuracy in force measurements, with profound implications for biological, biophysical, and materials science research. It enables the precise manipulation of cells and nanoparticles, opening new avenues for investigation in these fields.