Micromechatronics, Inc. (MMech)

www.mmech.com - Ph: 814-861-5688

SB Stack Actuators

200V Piezoelectric Stack Actuators

SB_Stacks

pdf-icon_sm SB Stack Specifications

Specifications:


SB Stack Specifications
Part Number
SB050510
SB050520
SB050540
SB070720
SB070740
Deflection (+/- 10%)
14 um
28 um
56 um
28 um
56 um
Length
10 mm
20 mm
40 mm
20 mm
40 mm
Dimensions
5x5 mm
5x5 mm
5x5 mm
7x7 mm
7x7 mm
Cap (+/- 20%)
450 nF
900 nF
2.1 uF
2.2 uF
4.3 uF
Mass 2.3 g
4.3 g
8.1 g
7.5 g
15 g
Blocking Force
700 N
700 N
700 N
1400 N
1400 N
Stiffness 120 N/um
60 N/um
28 N/um
51 N/um
102 N/um
Power Bandwidth with PiezoDrive Amplifiers (150V Sine Wave)
PDX150b 2.7 kHz
1.3 kHz
568 Hz
530 Hz
265 Hz
PDm200 216 Hz
108 Hz
46 Hz
21 Hz
42 Hz

Features

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, high speed, and exceptional reliability. The SB actuators are perfectly matched to the PiezoDrive PDX200b, PDQ200, PDL200, and PDm200 voltage and charge drivers.

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

 

Mounting Considerations

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.

SA-Mount_Contact_Force_med

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 -1BE, or -2BE to the order code. E.g. SA070718-2BE.

SA_Ball_End_90

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.

SA_eq1

where kp is the actuator stiffness and kL 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:

SA_eq2

Electrical Current Requirements

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:

SA_eq3

where Vp?p is the peak-to-peak voltage. For a triangle wave, the required peak current is equal to:

SA_eq4

Recommended Drivers

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

Connecting Wires

The connecting wires are 140mm long AWG2 insulated wires. Red identifies the positive terminal.

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.

SA_Dimensions_lg

Piezoelectric Properties

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

 

SA_piezoprops_med

More Information

200 Innovation Blvd. Suite 155
State College, PA 16803, USA
Ph: (814)-861-5688
Fax: (814)-861-1418
contact@mmech.com
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