More Piezo Information
Piezoelectric Nanopositioning Systems
Advantages of Piezoelectric Positioning Systems
Unlimited Resolution
A piezoelectric actuator (PZT) can produce extremely fine position changes down to the sub-nanometer range. The smallest changes in operating voltage are converted into smooth movements. Motion is not influenced by stiction/friction or threshold voltages.
Large Force Generation
PZT Actuators can generate a force of several 10,000 N. PI offers units that can bear loads up to several tons and position within a range of more than 100 µm with sub-nanometer resolution
Fast Expansion
Piezo actuators and piezostage systems offer the fastest response time available (microsecond time constants). Acceleration rates of more than 10,000 g's can be obtained.
No Magnetic Fields
The piezo effect is related to electrical fields. PZT actuators don’t produce magnetic fields nor are they affected by magnetic fields. They are specially well suited for applications where magnetic fields cannot be tolerated.
Low Power Consumption
The piezo effect directly converts electrical energy into motion only absorbing electrical energy during movement. Static operation, even holding heavy loads, does not consume power.
No Wear and Tear
A piezo actuator has neither gears nor rotating shafts. Its displacement is based on solid state dynamics and shows no wear and tear. PI has conducted endurance tests on PZTs in which no change in performance was observed after several billion cycles.
Non-Magnetic, Vacuum and Clean Room Compatible
Piezo actuators and piezostage systems are ceramic elements that do not need any lubricants and show no wear and abrasion. This makes them intrinsically non-magentic, clean room compatible and ideally suited for Ultra High Vacuum applications.
Operation at Cryogenic Temperatures
The piezo effect is based on electric fields and functions down to zero degrees Kelvin (with reduced specifications).
Applications for Piezo actuators and piezostage systems
Optics, Photonics and Measuring Technology
• Image stabilization
• Scanning microscopy
• Auto focus systems
• Interferometry
• Fiber optic alignment & switching
• Fast mirror scanners
• Adaptive and active optics
• Laser tuning
• Mirror positioning
• Holography
• Stimulation of vibrations
Disk Drive
• MR head testing
• Pole tip recession
• Disk spin stands
• Vibration cancellation
Microelectronics
• Nano-metrology
• Wafer and mask positioning
• Critical dimension measurement
• Microlithography
• Inspection systems
• Vibration cancellation
Precision Mechanics and Mechanical Engineering
• Vibration cancellation
• Structural deformation
• Out-of-roundness grinding, drilling, turning
• Tool adjustment
• Wear correction
• Needle valve actuation
• Micro pumps
• Linear drives
• Piezo hammers
• Knife edge control in extrusion tools
• Micro engraving systems
• Shock wave generation
Life Science, Medicine, Biology
• Patch-clamp drives
• Gene technology
• Micro manipulation
• Cell penetration
• Micro dispensing devices
• Audiophysiological stimulation
• Shock wave generation
Glossary
Actuator: A device that produces motion (displacement).
Blocked force:
The maximum force an actuator can generate if blocked by an infinitely rigid restraint.
Ceramic:
A polycrystalline, inorganic material.
Closed loop operation:
The actuator is used with a position sensor, providing feedback to the position servo controller compensating for nonlinearity, hysteresis and creep (see open loop).
Compliance:
Strain produced per unit stress. The reciprocal of stiffness.
Creep:
An unwanted positive or negative increase in the displacement over time.
Curie Temperature:
The temperature at which the crystalline structure changes from a piezoelectric (non-symmetrical) to a non-piezoelectric (symmetrical) form. At this temperature PZT ceramics looses the piezoelectric properties.
Domain:
A region of electric dipoles with similar orientation.
Drift:
See creep
HVPZT:
Acronym for High Voltage PZT (actuator).
Hysteresis:
Hysteresis is based on crystalline polarization effects and molecular friction and occurs when reversing direction. Hysteresis is not to be confused with backlash.
LVPZT:
Acronym for Low Voltage PZT (translator).
Multilayer actuator:
An actuator manufactured in a fashion similar to multilayer ceramic capacitors. Active ceramic material and electrode material are "co-fired" in one step. Layer thickness is typically on the order of 20 to 100 µm.
Open loop operation:
The actuator is used without a position sensor. Displacement roughly corresponds to the drive voltage. Creep, nonlinearity and hysteresis are not compensated for.
Piezoelectric Materials:
Materials that change their dimensions when a voltage is applied and produce a charge when pressure is applied.
Polarization:
The electric orientation of molecules in a piezoelectric material.
PZT: Acronym for Plumbum (lead) Zirconate Titanate.
Polycrystalline ceramic material with piezoelectric properties. Often used as an alternative to piezo.
Stiffness:
The spring constant (of a piezo actuator).
Translator:
An actuator that produces linear motion (displacement).
More information on Piezo Mechanisms and Design
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