Schematic illustration of the microforcemeter application in measuring the propulsion forces of different types of microswimmer: tubular sperm-motor (biohybrid), actuated by the sperm flagella; microjet (chemical), actuated by the generated bubbles; microhelices (physical), actuated magnetically. All microswimmers are guided magnetically. The microforcemeter inherits the mechanical properties and fabrication accuracy of the cantilever picospring employed for the characterization purpose above, resulting in a high measurement consistency. The force-sensing range and limit are both tunable by the picospring configuration and the laser power of TPL. We use the photoresist without MNPs to fabricate the microforcemeter, to avoid the influence of the magnetic field on the measurement accuracy.
