Piezocomposite actuators
Piezos for high forces!
Faster than resonant frequencies!

 variable lengths from millimeters to meter high forces up to 70 kN
 resonant frequencies up to 60 kHz

1. Piezocomposite actuators
Piezocomposites are linear high load actuators designed in a discrete joining technology. Their advantages lay
in high force generation and high stiffness. Another key advantage is the ability to use a variable selection ofpiezo-ceramics. This variety of thermal behavior, dynamics, voltage stress and Curie temperature allow piezocomposite actuators to be used in countless applications.

Applications of piezocomposite actuators
Piezocomposite actuators are used for:shakeractive vibration damping
 shock wave generation
 material testing short impulse excitation
featuresfeatures of piezocomposites (compared to conventional high load actuators)
construction of metal-ceramic-compound through discrete joining technology
 adaptation for special applications through choice of piezoceramic (d33; Curie Temp. loss factor)
 integrated temperature management for HT applications (thermostable)
 high shock resistance and high vibrational excitation through optimized construction
 adjustment of the internal preload

2. Piezoelectrical PIA impulse generators


adjustable impact parameters like energy/ acceleration/ deflection/
E < 4 Joule; a > 10.000g, ΔL up to > 100µm
high repeatability of the impact parameters, precise time behavior
pulse energies in the Joule range
variable collision- and repetition rate
lowest rising times in the µs‘s
pulse width at about 10 µs
precise triggering in the µs-range
contact between actuator and specimen before impulse

PIA impulse generators provide fast accelerations to test objects, structures and materials. A special dielectricalpiezoceramic is used for highly-effective piezo impulse generators with a high power density.
The impulse energy density is twice as much as the comparable ceramics for actuators.

physical explanation
When the piezo actuator is charged quickly (squarepulse), then the axial compression stress in the piezo
ceramic jumps to a large value.
This increase takes place instantaneously, and resultsin high acceleration with high strain rates. A locking
pressure emerges. As a result the piezo-rod expands inan accelerated manner. The piezo stack can build up a
propagating pressure front, in a coupled body.
Therefore the piezo stack-type actuator is an “activerod” which generates electrical power pulses when driven by mechanical shocks.
Image 1: Scheme of a symmetric acting shock generator
working in axial direction

Image 3: typical double-pulse shape withthe seismic mass

Image 2: Pulse shape of an impulse generator witha symmetrical arrangement

PIA-electronics - requirements of the electronic
High Voltage Pulser HVP controller
high impulse currents up to 400A
µs accurate triggering
 peak power up to 400kW
 rising times in the µs-range
The basic principle of the HVP amplifier is the following: A capacitor (multiple 100µF) is charged with a desired
voltage. The capacitor will be disconnected from its power supply and suddenly discharged through the piezoshock generator.
Currents reach several hundred Amperes for a short-term period. The voltage which is applied to the piezo thusincreases to 1000V within a few µs.

Image 4: schematic bipolar control of a power piezo actuator by a high-voltage-pulser (HVP)

Examples PIAactuator type

operating voltage[V]amplitude atmax. current[µm]

capacitymax. acceleration[m/s²]PIA 300/10/3

0 … 300

7140 nF> 100‘000

PIA 1000/10/7

0 … 1000

720 nF> 100‘000

PIA 800/35/80-200 … 800

80

6,6µF

> 100‘000

3. Piezoelectrical PiSha Shaker
frequency range up to over 100 kHz, depending on the configuration of the shaker
high accelerations up to 10’000 g
 amplitudes from microns to several hundred microns (depending on operating frequency)
 power modulation of several tens of kN(measured under blocking conditions – depending on shaker dimensioning, frequency of operation andinstallation conditions) compact dimensions of the piezoelectric structures down to the millimeter range
 high forces thermal management


Operating principle of piezoeletric shakers
Piezo shaker put the electrical excitation signal directly into a motion. Due to the operating voltage of the shaker,
the amplitude of the deflection is determined by the charging current and the speed of the shaker movement(in the sub-resonant mode). The internal structure of the shaker is adapted to the occurring high forces, pressuresand accelerations. So the shaker achieves a reliable operation under oscillation at a continuous load.

Comparisson piezo-shaker / electromagnetic shaker
Compared to their size, piezo shakers have a higher
stiffness and force potential at shorter travels than thatof electromagnetic shakers.
Further applications are miniaturized components,
where piezo technology offers higher power densities
and smaller sizes.
Standard-piezo actuators are normally adapted on
smaller dynamics like positioning tasks. To some extent,
they can also be used with low modulation for vibrational excitation.
However dynamic excitation with high power densities and high frequencies/accelerations require special
adaptations in order to achieve reliable operation.
Image 5: Workspaces of piezoelectric and electromagnetic
shakers in comparison.

Geo-Shaker:
for vibration - or pulse excitation of the ground and of buildings
coupling to the ground via base plate
force-generation: reaction / acceleration forcesin conjunction with seismic masses
 power electronics: amplifier RCV1000/7(peak power 7 kW) voltages up to 1000 V seismic mass up to 200 kg(depending on the frequency tuning) max. vibration 80 microns
 max. force modulation ca. +/-15 kN
 basic response: typically at 200 Hz(depending on the seismic mass)Image 6: Geoshaker with seismic mass

Micro-Shaker: Ring type
mounting arrangement by clamps oras seismic response type 1st resonance up to 100 kHz
 max. amplitude: ±5 μm (frequency dependant) max. force modulation up to 1000 Newton(when fixed with clamps)
 max. operating voltage: 150 V electrical supply:
broadband amplifier LE150/100 EBWImage 7: different micro-shaker. size comparison with thimble

Examples PiSha
actuator type

operatingvoltage[V]

oscillation
amplitude*[µm]

force modulation(blocking limit)[N]

1st resonant
frequency

PiSha 300/10/3

0 … 150

1,51800

30 kHzPiSha 1000/35/150**

0 … 100075±15‘000
with seismic mass

200 HzPiSha

0 … 150<51000100 kHz* frequency dependant** with seismic mass of 80 kg (176 lbs)

4.

Product range

4.1. Stack type actuators
PSt series - stack type actuators without casing and without preload

maximum force generation up to 50’000 N
temperature range from -60°C up to over +200°C
typemax.
stroke*[µm]

length[mm]

electrical
capacity[nF]

stiffness[N/µm]

resonant
frequency[Hz]

PSt 1000/10/7

12/7

920

300

60

PSt 1000/10/20

24/18

1845

150

40

further versions at www.piezo.eu
PSt 1000/35/60

80/60

542500600

20

PSt 1000/35/80

105/8072330045015* stroke at a voltage of -200 V to 1000 V/ 0 to 1000 V

PSt series - stack type actuators with casing and with preload
maximum force generation up to 50’000 N
ideally suited for dynamic application due to high preload temperature range from -60°C up to over +200°C
typemax.
stroke*[µm]

length[mm]

electrical
capacity[nF]

stiffness[N/µm]

resonant
frequency[Hz]

PSt 1000/10/7 VS18

12/7

24

20

300

40

PSt 1000/10/20 VS18

27/20

33

45150

35

further versions at www.piezo.eu
PSt 1000/35/150 VS45

200/150

154570220

7

PSt 1000/35/200 VS45

260/2001946500

150

4* stroke at a voltage of -200 V to 1000 V/ 0 to 1000 V

4.2. Ring type actuators
HPSt series - ring type actuators with casing and without preload
inside aperture for optical positioning and laser applications
improved cooling also available as 500V version with diameters 10-5 or 15-8


typemax.
stroke*[µm]

length[mm]

electrical
capacity[nF]

stiffness[N/µm]

resonant
frequency[Hz]

HPSt 1000/10-5/7

13/8

915

210

50

HPSt 1000/10-5/20

25/17

1840

110

35

further versions at www.piezo.eu
HPSt 1000/35-25/80105/80

721300250

12HPSt 1000/35-25/100

130/100901800

160

10* stroke at a voltage of -200 V to 1000 V/ 0 to 1000 V

HPSt VS series - ring type actuators with casing and with preload
free inside aperture
with internal preload: ideally suited for optical applications with high dynamics
 also available as 500V version with diameters 10-5 or 15-8


typemax.
stroke*[µm]

length[mm]

electrical
capacity[nF]

stiffness[N/µm]

resonant
frequency[Hz]

HPSt 1000/10-5/7 VS18

12/7241521035

HPSt 1000/10-5/20 VS1827/20

334011027further versions at www.piezo.eu
HPSt 1000/35-25/80 VS45

105/80891300250

12HPSt 1000/35-25/100 VS45

130/100

107180160

10* stroke at a voltage of -200 V to 1000 V/ 0 to 1000 V

4.3. Piezo-amplifier
1/3-channel-amplifier SVR 1000 - up to 1000Vfor static and quasi-static applications
max. current 8 mA low noise (~ 1mV at 0.47µF load) manual control of DC-offsets
The SVR 1000 is available as a multi-channel andsingle channel amplifier. Due to its low voltage
noise, it is excellent for positioning applications,especially for the positioning of optics.

switching amplifier RCV 1000/3 - up to 1000 V
high load switching amplifier systemmax. current 3A
 optionally up to 7A on request manual control of the DC-offset
The RCV 1000/3 is a switching amplifier with apeak power of 3 kW. It is ideally suited for dynamic control of high volume piezo-actuators andwith capacities in the µF-range.

5.

TheoryForce
In dynamic applications the generation of tensile andpressure forces are bound to the acceleration.   For asinu-soidal input signal the following formula applies:
F = forcem = moved massa = acceleration

ŝ = amplitude
f = working frequency

Frequencies
With specially designed piezo shakers from piezosystem jena it is possible to work above the resonant frequency.

The generated energy can reach several joules.

Shock pulse
The sock pulse (p) is the product of the mass which is
moved into the shock front and the particle velocity.
The shock pulse depends on the cross section of theactuator (A) and the used piezo ceramic (mechanicalstress σ).
 T
p=A·σt dt0According to the actuators configuration the shock
pulse can reach up to 1 Ns.

Particle velocity inside the piezo ceramic
The particle velocity matches the maximum displacement velocity of the elementary cell of the piezo ceramic. The particle velocity can reach several m/s.

Force generation at the beginning of thepulse

Actuators that work near or above the resonant frequency need to be prestressed. Please consider resonance magnification near the resonance frequency anddecrease in amplitude for higher frequencies.

Collision excitation
For highly effective piezo pulse generators with a highpower density a special piezo ceramic material is used.
The mechanical impact energy density of the usedceramic material is twice as high as the common ceramic material.
The mechanical energy content of the impact depends
on the ceramic material (piezoelectric charge constantd33, young modulus Y), the volume of the actuator (V)and the applied electric field (E).

For more information please visit:piezosystem jena GmbH phone: (+49) 3641 66880
fax:(+49) 3641 668866
Stockholmer Straße 12e-mail: info@piezojena. com
07747 Jena
GERMANYThe generated force at the beginning of the plunge
depends on the actuators cross section, the applied
electrical field strength and the type of piezo ceramic.
According to the actuators configuration the generated
force can reach several 10’s kN.

Pulse width
The pulse width depends on the runtime of the mechanical pulse in the actuator, the length of the actuatorand sonic velocity. According to the actuators configuration the pulse width reaches from a few µs to over
100 µs.

Achievable displacement of the plunger
The displacement of the plunger depends on the typeof piezo ceramic, the length of the piezo stack and theelectric field strength. According to the actuators configuration a displacement over 100 µm is possible.

www.piezo.eu
piezosystem jena, Inc.
2B Rosenfeld Drive
Hopedale, MA, 01747
USA

phone: (+1) 508 634 6688
fax:(+1) 508 634 6868
e-mail: usa@piezojena.com

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