Sterile Motors, Piezo Transducers: Precision Motion for Medical Design

13 Medical Applications for
Precision Motion and Piezo Motor Technology

	Brochure:
Precision Motion & Piezo Transducers in Pharmaceutical & Medical Devices

Piezo Laser Steering Mirror Mounts and Focusing Systems for Ophthalmology / Refractive Surgery

Piezo steering and fast focusing devices are used in Ophthalmology.

PI's compact piezo steering mirror mounts provide many advantages over classical beam deflection methods. Laser beam control and focusing requires high-precision positioning systems. Piezoceramic based solutions work with extreme precision and speed. They boast extreme reliability (PI piezo actuators are employed on the Mars mission), and compact size for easy integration in today's laser systems. Read: Advances in Piezo Mechanics and Eye Surgery

Piezo Motion & Engineered Nanopositioning Systems: Key to Nanometer Sized Features
Watch Video Webinar: Piezoelectric Transducers for Liquid Handling, IVD, PoC, Cytometry, Array Spotting

Miniature 6-Degree of Freedom Hexapod Robotics Positioner

Precision Handling, Testing, Assembly

Miniature hexapod positioners are perfectly suited for precision assembly and alignment applications of small, high precision parts. They provide extremely flexible motion in all degrees of freedom, plus a programmable center of rotation. PI hexapods come with an easy to use controller and software that provides them with motion flexibility similar to the human hand.

PI's H-810 and H-811 miniature 6-Axis positioners combines all advantages of PI’s high load tried and proven parallel-kinematic robot systems in the smallest of packages. With a diameter of only 10 cm and a height of less than 12 cm, the M-810 offers travel ranges of up to 40 mm in the XY plane and 13 mm in the Z direction. Despite of its small size, the hexapod can reliably position loads of up to 5 kg at velocities of 10 mm/s.

The small envelope was made possible by the usage of new technologies for encoders, motors and reference switches. Nevertheless, the Mini-Hexapod is 100% compatible with PI's tried and proven hexapod controllers and software.

As with other parallel-kinematics positioners from PI, the six high resolution actuators are connected directly to a single moving platform. The user is able to define the center of rotation (pivot point) independent of platform motion with a simple software command.

In contrast to conventional, stacked, multi-axis systems, there is no accumulation of guiding and lever-arm induced errors

Technical Specifications
and Order Info for the M-811 Miniature 6-Axis Hexapod

Read Hexapods Enable Precise 6-Axis Patient Positioning Couches for Radiotherapy

	Brochure:
Piezo in Pharmaceutical & Medical Devices

Piezoelectric Transducers and Assemblies for Micro Pumps and Valves Precison Dosing of Microliter Volumes
Piezo = Miniaturized Technology Displacement pumps are used worldwide in many diverse branches of industry. Increasing miniaturization means the market for their smaller “relatives“ is also growing: Microdispensers take on distribution and dosing tasks where small volumes in the milliliter, microliter or nanoliter range have to be controlled. Piezo is the Driving Force The design is based on the familiar principles of diaphragm pumps and valves and also makes use of the peristaltic principle. The miniaturized drives are based on piezoelectric actuators in various shapes and degrees of integration.		Wide Range of Applications for Flexible Technology In drug discovery and medical engineering, biotechnology or chemical analysis, tiny dispensers accurately dose active substances or medicines. Micropumps take care of the removal of reaction gases in closed processes. Read Article: Motion Control, Piezo Transducers, Motors for Medical Design Drive Solutions for Medical Design Catalog
Micro-Diaphragm Pumps Micro-diaphragm pumps operate in a similar way to piston pumps, but the medium to be transported is separated from the drive by a diaphragm. Passive inlet and outlet valves control the pumping direction. Piezo ceramic elements in disk form which are mounted directly onto a metal disk make ideal drive systems for micro-diaphragm pumps: This drive solution occupies extremely little space, and the piezo displacement can be very finely adjusted, to nanometers, allowing the pumped volumes to be very precisely defined.		Adapted for Precision & Force The properties of the pump media – viscosity and drop size, for example – determine the different forces which have to be applied and hence the size and type of the piezo actuator used. The piezo displacement is a variable parameter which controls the dosing volume. With micropumps, the frequency also determines the flow rate that can be achieved. Feature Article in European Medical Device Technology Magazine: Precise Liquid Handling for in Vitro Diagnostics Working principle of a piezoelectric diaphragm valve. Usually, valve applications require higher forces than pumps. The principle of peristaltic pumping makes directional valves obsolete; the pumping direction in this case is specified by the order in which the individual actuator elements are driven.

PiezoMove: Moving, Positioning, Scanning

Piezo linear actuators can be used in micro-valves, particularly where viscous liquids with a tendency towards higher back pressures are processed; where larger strokes of the valve tappet are required, with lever amplification as well.

Piezo = nano precision = exotic?
Piezoelectric actuators provide a lot more benefits than “just“ precision. Their excellent dynamics and high force also play a crucial role in many areas, where nanometer precision is not (yet) required: e.g. for fast switching, vibration cancellation, or to adjust tools in machines.

In these applications the piezo actuator is one – if not the only – solution and in the case of the new Piezo

Move OEM actuators, at a very attractive price.
PiezoMove OEM actuators: Apply motion, how and where it is required PiezoMove actuators combine guided motion and long travel ranges up to 1 mm and provide precision in the 10 nm range if ordered with the position sensor option. They are very compact, easy to integrate, require no maintenance and provide service life of Billions (10exp9) of cyles.

PI supplies a variety of standard integration levels and also customized versions: From simple piezo stack components and preloaded linear actuators through to 6-axis positioning systems with subnanometer precision.

Feature Article in EMDT Magazine: Piezo Motors and Actuators: Streamlining Medical Device Performance

P-602(l.) and P-603(r.) PiezoMove flexure actuators are ideal for applications in Adaptronics, Biotechnology, and Microfluidics.

Electrophysiology: Piezos Enable Faster Solution Switching

Siskiyou’s MXPZT-300A fast solution Switcher is based on a fast piezo flexure actuator

Electrophysiological studies require fast motions of a double- bore (theta-glass) pipette across cell membranes. With a cell held in a patch clamp and monitored electrically, one bore of the pipette flows a buffer solution, while the other carries a drug or other chemical. By quickly sweeping the pipette so one bore or the other suffuses the cell, its electrophysiological response can be correlated to the chemical environment. Piezos are ideal for fast switching, as they offer electromagnetic quietness, good repeatability, high reliability and fast speeds. However, fast acceleration can mean recoil forces excite vibration in the pipette and both piezo and stepper actuators have suffered from these in the past. These cause unwanted, repetitive solution switching for many milliseconds. Paper: Electrophysiology - Transducers Enable Faster Solution Switching

Ultrasonic Piezos Drive Medical Engineering

The continuing miniaturization in medical engineering places ever increasing demands on the components. Piezo drives are the solution for many motion control applications; the piezo effect efficiently generates fast and precise motion while requiring very little space.

Efficient Aerosol Generation with Piezoelectric Ultrasonic Transducers
The treatment of respiratory diseases often involves medications being administered directly with atomizers. One method of atomization is to generate very fine droplets with the aid of ultrasonic piezo transducers / ceramics. Specially shaped piezo ceramic discs excite a stainless steel diaphragm with several thousand holes to execute ultrasonic oscillations at more than 100 kilohertz: this produces particularly homogenous aerosols, allowing the medications to be dosed accurately and administered in a more targeted way. See difference between Hard Ceramic and Soft Ceramic (Low Voltage Multilayer) Ultrasonic Transducers.


An ultrasonic piezoelectric ring transducer disk produces the aerosol in the atomizer head of the eFlow® rapid Electronic Nebulizer series. (source: Pari Pharma GmbH)		Custom piezo disks precisely dose liquidsand gases in the ThinXXS micropump. (source: thinXXS Microtechnology AG)

Moreover, the piezoelectric transducer technology reduces the time required to atomize medications by up to 50 % compared to conventional systems increasing the quality of life for patients with chronic diseases.

Piezo ceramics meet the special hygiene requirements in medical engineering; the aerosol generators can be sterilized at high temperatures, even in autoclaves. The ultrasonic operation is soundless for humans, and the low power consumption of the piezo components allows battery operation.

High quality, ultra-clean piezo ceramic discs and tubes from PI Ceramic. These piezo elements find applications in micro pumps, nebulizers, ultrasonic transducers (medical imaging), stimulators etc.

Piezoelectric Drives in Microfluidics
Piezo-driven microdispensers, i.e. micropumps and microvalves, can dose minute volumes down to the microliter range with very high accuracy. Disk-shaped piezo elements mounted directly onto a metal microdiaphragm provide the highly dynamic drive for precision miniature liquid or gas pumps. Due to the separation of drive and medium through the diaphragm, interference with the pumped media is completely avoided.

Lab-on-a-chip applications are made possible by the minute dimensions.

Read: Ultrasonic Metering in Intensive Care Devices

Different Types of Piezo Actuators Solve Different Problems


Direct Actuators: Piezo Stacks, Shear (X, XY) Highest Force Fastest Response Travel Ranges 2-100 µm		Ampliied Piezo Flexure Actuators Flexure Guiding System Response <1 msec Travel to 2 mm, Compact

Ultrasonic Linear Motors Long Travel Fast: 350 mm/sec Low Profile, Self Locking		PiezoWalk® Linear Motors High Force (2 kg to 80 kg) Compact, Self Locking Long Travel
All: Sterile, Low Power, No Lubricants, Non- Magnetic, Vacuum Compatible; High Resolution: Sub-Nanometer to Sub-Micron

Non-Magnetic Motors


Ultrasonic Motor Fast: Max. Velocity to 500 mm/s, Acceleration up to 5 g Min. Incremental Motion to 0.05 µm Self-Locking No Electro-Magnetic Fields Integrated Actuators & Stages also Available Patented Principle		OEM PiezoWalk® Linear Motor Stepping Mode and Continuously Variable Mode 20 mm Standard Travel Range Resolution Microns to Nanometers (Depends on Version) Low Operating Voltage Self-Locking, Non-Magnetic, No Heat Dissipation, Very Stable Vacuum-Compatible, Compact & Cost-Effective Design		PiezoWalk® Linear Actuator Linear Actuator, Manipulator, Piezo Stepper Travel Range 30 mm Long Life: Ideal for Micro- and Nano-Manipulation Linear Encoder Option Very High Acceleration, e.g. for Cell Penetration Stepping Mode and Continuously Variable Mode Smooth Motion, no Closed-Loop Jitter Vacuum-Compatible and Non-Magnetic Versions

Dispensers for Bio-Handling

Low profile linear actuators, shown with well plate. The integrated ceramic piezomotor provides high speeds.

Piezo ultrasonic motors are compact, provide high speed and have other advantages compared to conventional motors and screw driven motorized actuators

– particularly when the stages must be small and fast. They achieve positioning accuracies of up to 0.1 µm and speeds of up to several 100 mm/s.

Small and fast is not only a requirement in classical micropositioning technology, however. Piezo ultrasonic motors are also extremely well suited to applications where the accuracy requirements are not quite so demanding – in the range between 5 and 100 micrometers for example, which is usually sufficient for industrial automation and handling tasks.

PI provides a number of compact actuators that can be used in precision dispensing application.