Nanonewton Force Measurements Based on Electromagnetic Force Compensated Balances (EMFC)

This paper gives an overview of microbalances that measure forces in the range of nanonewton and their applications. A loading force produces a deflection of the balance that is compensated by an actuator. The current (electromagnetic) or voltage (electrostatic) that is necessary to equalize the balance is a measure for the applied force. The TV-Ilmenau achieved a force resolution of less than 1 nN with a system that is working according to the electromagnetic force compensating principle. The force resolution is dependent on the stiffness of the balance joints and on the resolution of the balance deflection measurement. In order to increase the force resolution, the TV- Ilmenau develops a new system with a lower stiffness and a higher resolution of the position sensor.