# SB Series 200V Piezo Stack Actuators

The PiezoDrive SB stack actuators are high performance multilayer stack actuators with thermoplastic encapsulation for improved reliability and protection against dust and humidity. PiezoDrive actuators are designed for applications that require long range, high force, nanometre resolution, and high speed. The SB actuators are perfectly matched to the range of PiezoDrive amplifiers and driver modules.

Applications include: Nanopositioning, Microscopy, Precision Machining, Vibration Control, Hydraulic Pumps, Valves, and Optics.

### Specifications

 Order Code Range +/- 10% Length Dimensions Cap. +/-20% Mass Blocking Force Stiffness $USD Buy Now SB050510 14 um 10 um 5 x 5 mm 450 nF 2.3 g 700 N 120 N/um$39 Buy Now SB050520 28 um 20 um 5 x 5 mm 900 nF 4.3 g 700 N 60 N/um $81 Buy Now SB050540 56 um 40 um 5 x 5 mm 2.1 uF 8.1 g 700 N 28 N/um$162 Buy Now SB070720 28 um 20 um 7 x 7 mm 2.2 uF 7.5 g 1400 N 102 N/um $106 Buy Now SB070740 56 um 40 um 7 x 7 mm 4.5 uF 15 g 1400 N 51 N/um$213 Buy Now

### Mounting

Stack actuators should not be exposed to significant tensile loads, unequally distributed loads, off-axis loads, bending moments, or torque. To reduce mounting errors, a ceramic or stainless steel ball end can be used to interface the stack actuator to the load. Flexural mechanisms are also recommended.

The maximum recommended tensile load is 10% of the blocking force. In applications that require bi-directional forces or high speed motion, a preload force is recommended with a magnitude greater than the maximum tensile load. This gaurantees that the actuator is always in compression. The maximum recommended preload is 50% of the blocking force.

### Ball Ends

PiezoDrive stack actuators can be supplied with Saphire ball ends to improve the load distribution, simplify the mounting, and reduce bending moments during service. One or two ball ends can be specified by adding one of the following suffixes to the order code: -TBE (Top Ball End), -BBE (Bottom Ball End), or -2BE (Both Ball Ends). E.g. SA070718-2BE.

 Actuator Width Ball End Diameter Additional Length 3 mm 3 mm 3 mm 5 mm 5 mm 5 mm 7 mm 6.5 mm 6.5 mm

### Range

The range is specified for an applied voltage of -30V to +150V. If the input voltage is unipolar (0V to +150V) the specified range is reduced by a factor of 0.75. When a stack actuator is driving a stiff spring, the range is reduced by the factor
$$\frac{k_p}{k_p+k_L}$$ where $$k_p$$ is the actuator stiffness and $$k_L$$ is the load stiffness.

The travel range can also be reduced by restraining the end plates, e.g. by bonding the actuator to a stiff base. This effect is most significant in actuators that have a length less than twice the width.

### Capacitance

The actuator capacitance is the small-signal capacitance measured at room temperature. Due to hysteresis, the effective capacitance increases with applied voltage. When operating at full range, the effective capacitance is approximately twice the small-signal capacitance. The capacitance also increases with temperature. A temperature increase of approximately 50 degrees C will double the effective capacitance.

### Thermal

Piezoelectric actuators dissipate heat when driven at full range with a high frequency. PiezoDrive actuators can be operated continuously at temperatures up to 85 degrees C. Continuous operation beyond this temperature may damage the actuator.

The dissipated heat is approximately 10% of the applied electrical power. For a sine-wave, the applied electrical power is:
$$P = \frac{V_{p-p}^2 \pi C f}{4}.$$

### Electrical Current Requirements

Power Bandwidth Calculator

The required current is $$I = C~ dV/dt$$ where $$I$$ is the current, $$C$$ is the effective capacitance, and $$dV/dt$$ is the voltage rate of change. For a sine-wave, the required peak current is equal to:
$$I_p = 2 \pi f V_{p-p}$$ where $$V_{p-p}$$ is the peak-to-peak voltage. For a triangle wave, the required peak current is equal to:
$$I_p = 2 C f V_{p-p} .$$

### Connecting Wires

All of the connecting wires are 100mm AWG26 PTFE insulated wires, except for the SA030306 actuator which has 15mm leads. Other lengths are available on request. Red identifies the positive terminal.

### Vacuum Compatibility

The SA Actuators are supplied with either vacuum compatible polymer encapsulation or a UV cured lacquer coating. Both coatings and the wiring insulation meet the outgassing requirements for NASA SP-R-0022A.

### Options / OEM Customization

• Ceramic ball ends (Order suffix – 2BE)
• Custom range and dimensions
• Custom wiring arrangement / connectors
• Preload or mechanical amplifier mechanisms

### Dimensions

The total stack dimensions are based on the width and length of the ceramic listed in the specifications. The length specification includes the piezoelectric stack and two 1-mm thick ceramic end plates.

 Amplifier Application PDm200B General purpose, low cost MX200 High Current, Low noise, low cost PDu150 Ultra-low noise PD200 High speed, low noise PX200 High current, low noise

### Piezoelectric Properties

The piezoelectric material is similar to PZT-5H and Navy Type VI.

Property Symbol Value Unit
Piezoelectric constants d33 600 10-12 m/V
d31 -270 10-12 m/V
g33 19.4 10-3 Vm/N
g31 -9.2 10-3 Vm/N
Electro-mechanical
coupling coefficients
Kp 0.65 NA
Kt 0.37 NA
K31 0.38 NA
Frequency constant Np 1980 Hz-m
Nt 1950 Hz-m
N31 1450 Hz-m
Elastic constant Y33 5.3 1010 N/m2
Y11 7.2 1010 N/m2
Q Factor Qm 80 NA
Dielectric constant e33 ⁄ e0 3500 @1 kHz
Dissipation factor tan δ 2.5 % @ 1 kHz
Currie Temperature Tc 220 C
Density ρ 7.8 g/cm3

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