Python™

High performance piezoelectric bender

Problemscracking

More than 90% of piezoelectric actuator failures are due to cracks. Micro cracks are often created in the piezoelectric wafer during the manufacturing process already. Under normal operation (deflection) the inertial force experienced by the piezo actuator (particularly when driven by DC and “rectangular” signal pulses) can induce high cyclic stress (tensile/compression) onto the piezo layer. As the layer consists of a brittle, ceramic material the micro cracks begin to grow under this cyclic stress, causing a reduction in performance of the piezo actuator. These cracks eventually propagate throughout the entire wafer, resulting in total failure. Cracks may also be caused by thermal shocks associated with soldering, handling and other mechanical impact.

ProblemsDielectric Breakdown

Most metals used in piezo electrodes (such as Ni or Ag) can migrate along micro cracks and grain boundaries of the piezo material under conditions of high humidity and applied voltage. This electrochemical migration results in dendrite growths and eventually leads to short circuiting within the piezo layer.

 

SolutionMeet the Python™ Family

Originally designed as a piezoelectric artificial muscle for our biomimetic cooling fans, the Python™ piezo bender addresses and solves for all the issues above. This gives the Python™ superior reliability when compared to conventional piezoelectric actuators, sensors and energy harvesters.

ReliabilityDouble Layer protection

With Python™ technology the piezo layer is hermetically sandwiched between two durable epoxy resin layers. This sandwich-like structure is carefully engineered to give the piezo layer significant negative pre-stress. This compressive stress helps hinder the development of micro cracks and further prevents propagation of cracks during operation. The epoxy resin layers also protect the piezo actuator from handling stress and accidental drops or impact. The Python™ bending actuator is further conformally coated with two thin silicone rubber layers to protect the piezo layer from humidity and condensation.

 

PerformanceHighly Optimized

The Python™ piezo actuator is the result of many years of research by our engineers in collaboration with our university research partners. The material and thickness of each layer has been optimized using advanced FEM simulations and experiments in order to yield maximum displacement at a given bending stiffness. The optimization process also ensures the piezo layer always operates within its material strength limitations, even at extremely high displacements, allowing Python™ actuators to simultaneously achieve high reliability and optimal performance.

Connection & IntergrationIsolated piezo layers

  • Isolated electrical connection: Soldering directly onto the piezo layer can cause cracks and failure due to thermal shock. That is why the Python™ bending actuator comes with thermally isolated solder pads to prevent this risk.
  • Convenient mechanical integration: Similarly, clamping directly onto the brittle piezo layers may also cause cracks and failures. Therefore the Python™ piezo actuator includes passive extended portions at both ends. These parts can be drilled, machined, and clamped for mechanical integration without any impact on the actual piezo layers.

QualityRigorous Testing

The Python™ actuator has undergone comprehensive and strenuous testing to validate its superior quality and reliability. Our accelerated life tests show that the Python™ bender can achieve more than one billion deflection cycles without any degradation in performance. Moreover, every single Python™ actuator goes through a minimum 10,000 cycle “burn-in test” before being shipped to our customers, ensuring no premature failures in the product.

ModelPython™ Unimorph

Descriptions

The Python™ Unimorph consists of one piezo layer attached to a substrate, and encapsulated by protective layers. When positive voltage is applied, the piezo layer contracts in a horizontal direction inducing upward bending deflection. Negative voltage with lower amps can also be applied to induce downward bending deflection. The Python™ Unimorph has a dome shape allowing its piezo layer to take on additional compressive pre-stress, resulting in superior reliability.

 

Stackup

Silicone rubber
Epoxy resin
PZT
Substrate
Epoxy resin
Silicone rubber

Unique Features

ModelPython™ Bimorph

Descriptions

The Python™ Bimorph consists of two piezo layers attached to the top and bottom surface of a substrate, and encapsulated by protective layers. When positive voltage is applied to the top piezo layer, it contracts in an in-plane direction inducing upward bending deflection. Similarly, when positive voltage is applied to the bottom piezo layer, the layer contracts in an in-plane direction inducing downward bending deflection. Negative voltage with lower Amps can also be applied to induce downward bending deflection. The deflection behavior is bi-directional and symmetrical. Negative voltage can also be used along with positive to achieve additional bending deflection.

Stackup

Silicone rubber
Epoxy resin
PZT
Substrate
PZT
Epoxy resin
Silicone rubber

Unique Features

ModelPython™ Energy Harvester

Unlike conventional piezo energy harvesters which usually include one or two bare piezo layers attached to a substrate, the Python™ Energy Harvester includes a protective layer with a non-uniform thickness. The varying thickness of this layer is optimized so that the Python™ Energy Harvester receives more uniform stress and strain distributions on the piezo layer under bending conditions. This allows the Python™ Energy Harvester to harvest up to 3x more electrical energy through bending / vibration, while maintaining lower stress levels and therefore higher reliability when compared to conventional harvesters.

Biomimetic piezo actuator energy harvester

Common FeaturesAll models come with the following common features

Standard sizes

 UnitTolerancePBA24RO-5H200PBA3008-5H200PBA3014-5H200PBA3020-5H200PBA6008-5H200PBA6014-5H200PBA6020-5H200PEH3020-5H250PEH6020-5H250PUA3008-5H200PUA3014-5H200PUA3020-5H200PUA6008-5H200PUA6014-5H200PUA6020-5H200
Type--BimorphBimorphBimorphBimorphBimorphBimorphBimorphHarvesterHarvesterUnimorphUnimorphUnimorphUnimorphUnimorphUnimorph
amm±0.424 (dia.)4646507676805585464650767680
bmm±0.220 (dia.)3030306060603060303030606060
cmm±0.288108810101088108810
dmm±0.2814208142022228142081420
Thicknessmm±0.10.650.650.650.650.650.650.650.700.700.540.540.540.540.540.54
Dome-heightmm±0.200000000.651.60.450.450.451.31.31.3
Massg±0.11.240.821.522.351.542.844.232.003.460.591.121.581.021.832.87
Displacementmm±15%±0.046±0.39±0.43±0.48±1.34±1.52±1.69±3.7mm *±9mm *-0.15 to +0.42-0.15 to +0.42-0.15 to +0.42-0.68 to +1.85-0.68 to +1.85-0.68 to +1.85
Blocking forceN±15%1.420.150.290.480.070.140.23--0.180.300.490.080.140.24
ResonanceHz±15%864021921921958585826892271271271656565
Piezo MATPZT-5HPZT-5HPZT-5HPZT-5HPZT-5HPZT-5HPZT-5HPZT-5HPZT-5HPZT-5HPZT-5HPZT-5HPZT-5HPZT-5HPZT-5H
Piezo thicknessmm±10%0.20.20.20.20.20.20.20.250.250.20.20.20.20.20.2
CapacitancenF±15%765290142104180284551102645715290142
Operating voltV--90 to +160-90 to +160-90 to +160-90 to +160-90 to +160-90 to +160-90 to +160±25V @±3.7mm **±25V @±9mm **-90 to +160-90 to +160-90 to +160-90 to +160-90 to +160-90 to +160
Operating TC--20 to 85-20 to 85-20 to 85-20 to 85-20 to 85-20 to 85-20 to 85-20 to 85-20 to 85-20 to 85-20 to 85-20 to 85-20 to 85-20 to 85-20 to 85

* Allowable applied displacement/deflection.

** Generated voltage measured at max allowable displacement, 1Hz. The energy harvester is clamped at one end, while the other end is displacement controlled.

– Tip displacement and blocking force are measured at the max operating voltage, and the actuator is clamped at one end.

– Resonance frequency is measured with 20 Vp-p. The actuator is clamped at one end, while the other end is unloaded.

 

Typical applications

SamplePricing

For low, experimental quantities you can order any of our standard Python™ models using the shopping cart below. For higher quantities please contact us at sale@bimitech.com to request a quote.

Filters Sort results
Model
Descriptions
Availability
Price
Quantity
24mm dia. x 0.65 mm thick bimorph bender
In stock
$215.00
46x8x0.65 mm³ bimorph bender
In stock
$95.00
Piezo actuator bender
46x14x0.65 mm³ bimorph bender
In stock
$105.00
50x20x0.65 mm³ bimorph bender
In stock
$115.00
76x8x0.65 mm³ bimorph bender
In stock
$115.00
Piezo actuator bender
76x14x0.65 mm³ bimorph bender
In stock
$125.00
Piezo actuator bender
80x20x0.65 mm³ bimorph bender
In stock
$135.00
55x22x0.70 mm³ energy harvester
In stock
$125.00
85x22x0.70 mm³ energy harvester
In stock
$145.00
46x8x0.56 mm³ unimorph bender
In stock
$75.00
Piezo actuator bender
46x14x0.56 mm³ unimorph bender
In stock
$85.00
50x20x0.56 mm³ unimorph bender
In stock
$95.00
76x8x0.56 mm³ unimorph bender
In stock
$95.00
Piezo actuator bender
76x14x0.56 mm³ unimorph bender
In stock
$105.00
Piezo actuator bender
80x20x0.56 mm³ unimorph bender
In stock
$115.00
QtyDiscount
2-420%
5+30%

* Most of standard items are in stock and usually shipped within one business day.

* Free shipping in the US on all orders. $30 international flat rate shipping. More information about shipping here.

* Not for personal use applications.

 

CustomizationAny size, shape, perfomance