Advantages
- High-precision force mapping measurement is possible for soft samples such as biological samples (e.g. cells).
- Easy to adapt to existing AFM by switching to the new mode without changing the mechanical configuration.
Technology Overview & Background
AFM (atomic force microscopy) is widely used to image the surface topography of a sample on a nanoscale and to measure the mechanical properties of the sample surface. In force mapping, the elastic modulus (stiffness) of samples is estimated from force-indentation curves, in which the maximum loading force is controlled to be constant. Therefore, the indentation depth changes depending on the elastic modulus at measurement locations, leading to damage to fragile samples (e.g., living cells) with heterogeneous mechanical properties and inaccurate mechanical measurements.
To solve this problem, the control of indentation depth, rather than indentation force, to be constant is desired. In principle, the indentation depth can be determined using the contact point between the AFM probe and the sample surface. However, for soft samples such as cells, the contact point is not precisely determined, resulting in a decrease in the measurement accuracy of the sample elasticity. Therefore, the direct control method of determining indentation depth is required without using the measured contact point.
The researchers devised a new method that enables constant control of indentation amount without using contact point information. This method can be applied without changing the conventional AFM configuration, only changing the measurement mode.
Data
Using a monolayer of Madin-Darby Canine Kidney cells (MDCK cells) seeded in a paving stone-like pattern as the measurement sample, AFM force mapping measurements were performed with a constant conventional indentation force and with a constant controlled indentation volume of the present invention, and the results of each were compared, confirming the validity of the present method.
Publication(s)
Papers being submitted for publication.
Patent(s)
A patent applied in Japan.
Principal Investigator & Academic Institution
Takaharu Okajima, DSc (Professor, Hokkaido University, Japan)
Development Stage & Future Research Plans
The above is validation data using the researcher’s own AFM, and details of the invention and specific measurement data can be disclosed by signing a Confidentiality Agreement (CDA) with Hokkaido University.
Expectations
TECH MANAGE is now looking for companies to collaborate with the researcher(s) and develop this technology further under the licensing of the related patent(s) described above.
It could also consider joint research using the invention, providing detailed information and know-how based on a CDA, a time-limited option agreement for evaluation, or setting up a license option.
Project ID: JT-05065