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Piezoelectric Benders![]()
PB4VB2W Piezoelectric Bimorph Bender PB4NB2S Piezoelectric Bimorph Bender with Wires and Holder, ±450 µm Displacement Holder with Two Ø4.3 mm Through Holes for Mounting the Piezoelectric Bender PB4NB2W Piezoelectric Bimorph Bender 32 mm 20 mm Related Items ![]() Please Wait
![]() Click to Enlarge These bimorph piezoelectric benders flex when a voltage is applied. Please see the Operation tab for details. Features
Thorlabs' Piezoelectric Benders provide a tip deflection whose magnitude and direction is a function of the applied bias voltages. This is useful for applications such as wire bonding, electrical switches, beam deflection, valves, and acceleration sensors. Featuring either a 16 mm or 28 mm active free length, these bimorph benders provide displacements of up to ±135 µm and ±450 µm, respectively. The piezo benders include three pre-soldered wire leads, and are available without a holder or pre-mounted in a rigid PEEK (polyether ether ketone) holder. For more information on mounting recommendations for the bare piezos, see the Operation tab. The pre-attached PEEK holder features two Ø4.3 mm through holes on 12.5 mm centers that accept 8-32, M3, or M4 screws. This holder it is not detachable. Single-Side Voltage Control
![]() Click to Enlarge Differential Voltage Control
![]() Click to Enlarge These actuators can be controlled using either single-side or differential voltage control. An example of each is illustrated above, and more options are described in the Operation tab.
Piezo Operation Any voltage driver with a voltage limit of at least 150 V can be used to drive these piezo bender actuators. Electrical connections to the three electrodes are located on the top surface, and each electrode is connected to a wire lead; the electrode connected to the red lead should always be positively biased and is marked with a silver plus sign. Providing a bias over only the top or bottom layers can be used to operate the bender in single-side voltage control mode, when deflection is limited to one direction. Providing different bias over these two sets of layers enables deflection in either direction. Examples of these cases are shown below. Do not apply a voltage bias in excess of 150 V between any two leads, as this can damage the bender. For details on the different voltage control modes, see the Operation tab. Note: The bare piezoelectric actuators are compatible with vacuum environments of >10-7 Torr. The versions pre-attached to a PEEK holder are not recommended for use in vacuum environments. Piezoelectric benders with custom dimensions and voltage ranges are available. Additionally, we support high-volume orders. Please contact Tech Support for more information. ![]() Click to Enlarge Dicing the PZT Block into Individual Elements ![]() Click to Enlarge Chips After Binder Burnout and Sintering Thorlabs' In-House Piezoelectric ManufacturingOur piezoelectric chips are fabricated in our production facility in China, giving us full control over each step of the manufacturing process. This allows us to economically produce high-quality products, including custom and OEM devices. A glimpse into the fabrication of our piezoelectric chips follows. For more information about our manufacturing process and capabilities, please see our Piezoelectric Capabilities page.
![]() Click to Enlarge Figure 1: The active area, which expands in response to the applied voltage, is measured from the end of the piezo towards the silver plus sign. The inactive area does not respond to the applied voltage. Operation NotesMounting We recommend attaching the piezo bending actuator to a rigid holder (ceramic, PEEK, etc.) in order to maintain elastic compliance and avoid additional drift cause by deformation of the holder. When selecting a holder, ensure that the contact surfaces are sufficiently flat to allow proper attachment of the bender. If a metal holder is used, ensure that the contact area between the piezoelectric bender and the holder is insulating in order to prevent short circuits that can be caused by contact between the three external electrodes and the metal holder. ![]() Click to Enlarge Figure 2: If using a clamp to mount the PB4VB2W or PB4NB2W, the clamp should be applied to the approximately 1.5 mm wide portion of the inactive area located between the center of the + mark and the edge of the electrodes. When using glue to mount the bender, ensure that the glued contact surface is restricted to cover only the inactive part of the piezo bender, shown in Figure 1, in order to avoid reducing the stroke. Adhesive with a low Young's modulus is recommended for mechanical assembly, and the curing temperature should be as low as possible to reduce thermo-mechanical stress in the support. If mounting by mechanical clamping, the clamping pressure should be as low as possible while maintaining the mechanical stability of the assembly, approximately 5 times the specified blocking force. To achieve full stroke and avoid damaging the wire connections by crushing the solder points, apply the clamp to the region of the inactive area between the electrodes and the center of the + mark, as illustrated in Figure 2. Electrical Connections Caution: After driving, the piezo is fully charged. Directly connecting the green and white wires or red and white wires has the risk of electricity discharging, spark, and even failure. We recommend using a resistor (>1 kΩ) between the wires to release the charge. Soldering Wire Leads to the Electrodes
Driving Modes Single-Side Voltage Control With the bimorph bender oriented so that the plus sign faces up, a positive voltage between 0 and 150 V applied to the red wire will cause top layers to elongate while the length of the bottom layers remains the same. The unfixed end of the bender flexes downwards, as shown in Figure 3a, as the applied voltage increases. If a negative voltage between 0 and -150 V is applied to the green wire, the bottom layers elongate while the top layers do not change length. The unfixed end of the bender flexes upwards, as shown in Figure 3b. When using single-side voltage control, never vary the voltage on both the red and green lead at the same time, as a voltage difference of more than 150 V between these two leads will damage the actuator. Differential Voltage Control Differential voltage contol of the piezo bender can be performed by configuring the device as described by Option 3 or Option 4 in the table. For both driving configurations, a 150 V voltage difference is established between the red and the green wire and the maximum displacement is reached. In the case of Option 3, this is accomplished by holding the red wire at 150 V and the green wire at 0 V, while the voltage on the white wire is varied between 0 and 150 V. In the case of Option 4, the red wire is held at 75 V and the green wire at -75 V, while the voltage on the white wire is varied from -75 to 75 V. For example, if the PB4NB2W piezo bender actuator is configured according to Option 3 and the voltage applied to the white wire is 75 V, the magnitude of the voltage applied across the top and bottom layers is the same: the elongation of the top and bottom layers are the same and there is no displacement of the tip. When 0 V is applied to the white wire, the top layer elongates, the length of the bottom layer does not change, and displacement is 450 µm downwards. When 150 V is applied to the white wire, the bottom layer elongates, the length of the top layer does not change, and displacement is 450 µm upwards. For intermediate voltages applied to the white wire, the top and bottom layers elongate to different lengths and the magnitude and direction of the displacement varies accordingly. Long Term Operation
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