# SiMFlex Micromanipulation Cell with Modular Structure
## 4 SiMFlex Prototype and Testing  
A prototype for SiMFlex cell was designed with three linear translation stages (Figure 5). The linear movement along y axis is provided by the translational module which is a linear flexure stage with differential micrometer and a piezo drive with strain gauge feedback. The overall dimensions of the module are: \(139\times 75\times 29.5\) mm. A maximum displacement of 5 mm is ensured by differential micrometers which also provide fine and coarse adjustments. The fine adjuster travel is 300 \(\upmu\)m with an accuracy of 1 \(\upmu\)m. At any position ensured by the differential micrometer, a maximum displacement of 20 \(\upmu\)m provided by the piezo drive can be added. In this case, the strain gauge feedback offers a theoretical resolution of 0.6 nm. The translational movements along the \(\times\) and z axis are ensured by another two-axis miniature dovetail stage with M3 \(\times\) 30 mm lead screws [14]. The overall dimensions for this module are: \(58\times 43\times 72.4\) mm and the maximum displacements ensured are 12.7 mm on each axis. Figure 4: Displacement–voltage characteristic of SiMFlex micromanipulator various configs. The micromanipulation system had only the main compliant gripper and the piezoelectric bender with \(\pm 450\)\(\upmu\)m displacement or interchangeable jaws can be attached to it. The input from the main compliant gripper came from the piezoelectric stack actuator with \(6.5\times 6.5\times 18\) mm overall dimensions and the maximum \(15\)\(\upmu\)m stroke along the \(\times\) axis, when 100-V tension was applied. Also, the technical description has a hysteresis \(\pm 12\%\) from stroke [15]. The experimental study was focused on the displacement response of the piezo actuator by usingsinusoidal signals. Figure 5b shows the picture of the testing bench with laser sensors. The first measured test was for the input signal by main compliant gripper which came from stack piezoelectric actuator. In the case of the stack piezoelectric actuator, there is a sinusoidal signal with a value of 20 V that has a result of a 4 \(\upmu\)m displacement stroke. Also, there was also applied 100 V, which resulted in a 13 \(\upmu\)m displacement stroke (Figure 6a). The for voltage/displacement charts are presented in Figure 6b. The second measured test was for the output signals at the compliant gripper jaws level. The measurement was realized for the left and the right arm separately. For the left arm, when at  
Figure 5: SiMFlex micromanipulation cell: (a) prototype and (b) testing bench. Figure 6: Microgripper input displacement; (a) displacement hysteresis and (b) time response. stack piezoelectric actuator, a sinusoidal signal with of 100 V amplitude was applied and a 45 \(\upmu\)m displacement stroke resulted (Figure 7a). Also, the values for voltage/displacement versus time are presented in Figure 7b. Similar test was performed for the output signal of the right arm of the compliant gripper. A sine wave of 100 V amplitude was applied and 44.8 \(\upmu\)m displacement stroke resulted (Figure 8a). The values for voltage/displacement versus time are presented in Figure 8b. The final measurement test was at the border jaws, which are the end-points of the compliant gripper mounted as in Figure 2. Thede bending actuators were tested separately, the piezostack being kept at 0 V. When a sinusoidal signal with value \(\pm\)75 V was applied on the piezoelectric bender and  
Figure 8: Right arm output displacement: (**a**) displacement hysteresis and (**b**) time response. Figure 7: Left arm output displacement: (**a**) displacement hysteresis and (**b**) time response. 375 \(\upmu\)m displacement strokes resulted (Figure 9a). The voltage/displacement values versus time are presented in Figure 9b. Additional experimental testing with micro objects manipulated with the different shapes of jaws are performed according to the methodology developed by the authors of [16; 17; 18].