Case Study

Small Forces with Major Impact

Case Study
Researchers are investigating the uplift force of fruit flies
Researchers are investigating the uplift force of fruit flies

 

How much uplift force does a fruit fly need to fly?

Microforce sensors enable scientists to answer such questions and even to measure extremely small forces. At the Swiss Federal Institute of Metrology (METAS), a microbalance developed by METTLER TOLEDO now helps to calibrate small sensors.

 

Micro force sensors can be used in many fields, such as robotics, biology, medicinal applications and many more. "There is a general tendency to measure in ever smaller units of measure with the least possible uncertainty," according to Javier Levitt of SPG Metrology. Developing new products in micro and nanotechnologies demands accuracy and comparability. However, until recently it has not been possible to traceably calibrate micro force sensors.

 

 

A modified version of the XP6U Micro Balance is the very heart of the test station. (Source: METAS)
A modified version of the XP6U Micro Balance is the very heart of the test station. (Source: METAS)

To overcome this, the METAS Laboratory "Mass, Force and Pressure" started a research project in 2013 aiming to develop a traceable calibration method for small sensors.

"An industrial partner asked us if we could create a calibration device for the microforce sensors that they produced," reported Stefan Russi. He is an expert in microtechnology at METAS and supervised the project, together with his colleague Manuel Aeschbacher.

Internal Collabration

To understand how other measurement engineers carry out the calibration of tiny sensors, the two engineers exchanged knowledge and ideas with such experts as those from Korea and the National Metrology Institute of the Federal Republic of Germany [Physikalisch-Technischen Bundesanstalt - PTB].

 

After a visit to the PTB, Russi and Aeschbacher decided on which components they wanted to use for their experimental setup and where these were available on the market. This is how they came into contact with METTLER TOLEDO.

While at a LabTec workshop with SPG Metrology, the METAS team decided to base their experimental setup on the XP6U Micro Balance. "What made this balance special is that it had to be modified.

METTLER TOLEDO was very cooperative and we had a good working relationship. We are very grateful to them," said Stefan Russi.

Thanks to the successful cooperation, METAS can now offer traceable calibration of micro-force sensors. A comparison of measurements with PTB has confirmed the reliability of the new method.

Now the Swiss metrology experts have sought approval for the procedure from the International Bureau of Weights and Measures (BIPM). The new calibration method should soon be included in the BIPM database.

Since 2013, Stefan Russi and Manuel Aeschbacher (from left) have been working on making the traceable calibration of micro force sensors a reality
Since 2013, Stefan Russi and Manuel Aeschbacher (from left) have been working on making the traceable calibration of micro force sensors a reality

Since 2013, Stefan Russi and Manuel Aeschbacher (from left) have been working on making the traceable calibration of micro force sensors a reality