Micromechanical Testing - Micro force sensors and microgrippers

The basic principle of FemtoTools’ force sensors and grippers is a comb-like array of capacitor electrodes within a frame structure with the force sensor mounted with four springs on the outer frame. If the sensor is moved relatively to the outer frame, for example by applying force to it, the distance between the capacitor plates changes. This change is translated into a 0 – 5 V analog signal. This principle is also used to open and close the microgrippers by applying a voltage and thus changing the distance between the capacitor plates.

Micro force sensor FT-S series

The three micro force sensors of the FT-S series FT-S100, FT-S1000 and FT-S10000 cover the range of 5 nN to 10 mN. The sensors allow both tensile and compression testing with a guaranteed 300 % overload protection. The individual calibration of each sensor in combination with an outstanding long-time stability ensures unsurpassed measurement accuracy in this force range. A calibration data sheet is provided with each individual sensor.

FT-S100: force range +/- 100 µN with a resolution of 5 nN
FT-S1000: force range +/- 1000 µN with a resolution of 50 nN
FT-S10000: force range +/- 10 mN with a resolution of 0,5 µN

Microgripper FT-G series

The FT-G microgripper series has been developed to handle micro- to nanometer-sized objects. The standardized distances between the gripper arms are 30 µm, 60 µm and 100 µm, but they may also be customized to 400 µm. The gripper opening can be controlled with nanometer precision so that the gripper is fully closed at maximum actuation voltage.

Both the FT-G32 and the FT-G102 feature an integrated force sensor to measure the gripping force.

FT-G32: initial Opening 0 – 30 µm with force-feedback
FT-G102: initial Opening 0 – 100 µm with force-feedback
FT-G62: initial Opening 0 – 60 µm without force-feedback

Controller and software

FT-SC01 Force acquisition system

Both the FT-G32 and the FT-G102 feature an integrated force sensor to measure the gripping force.

The FT-SC01 is connected to a PC by a standard USB interface. An intuitive graphical user interface FT-WS01 force sensing software (p54) as well as the LabVIEW building blocks (VIs) are included, allowing operation in, and integration into existing measurement systems.

FT-GC01 Gripper controller

Both the micro force sensor and microgrippers may be read with the FT-GC01 gripper controller. This high-voltage controller may operate up to three grippers at the same while simultaneously measuring the gripping force. By default, the gripper arms are set to ground potential. The controller is connected to a PC by a standard USB interface. An intuitive graphical interface software FT-WS01 and LabVIEW building blocks (VIs) are included and allow the simple integration into existing measurement and manipulation systems.