The high speed combined with the virtually unlimited position resolution in the nanometer range provides advantages in open/close speed of valves and also in the dosing precision.
Piezo flexure amplified actuators provide motion ranges of several 100µm and extremely fast mechanical response to drive signal changes in the order of milliseconds and below.
Piezo mechanics are stiffer and can move faster than solenoids. Principle design of a high-speed precision dosing valve for micro-liter to picoliter applications. Piezo flexure actuators with built-in motion amplifier can implement valves that need larger strokes. In this method, piezo tube that contracts radially upon voltage application is available. Piezo mechanisms generate high kinetic energy, which can produce extremely small droplets without the associated nebulization, dripping, or satellite formation.ĭrop-on-demand method is similar to ink jet technology. It is preferred to have frequencies in the kilohertz range, and piezo actuators are capable of providing faster response when compared to electromagnetic drives, such as voice coils or solenoids. Usually, the rapid opening and closing of a valve is proportional to the amount of volume to be controlled. Devices like piezo-actuators are employed in a number of drives – either they can directly operate the valves or operate against a flexible tubing or strong springs to displace liquid volumes. Micro-dosing valves meant for nanoliter or picoliter droplets are dependent on extremely fast actuation. P-604 low-cost piezo flexure OEM actuator (Image: PI) (left) Piezoceramic disks can be attached to the membrane of a micropump and thus move it with high frequency.(Image:PI) (right) Piezo-transducer driven micro-diaphragm pump for laboratory automation (Image: thinXXS Microtechnology AG) Micro-dosing valves with piezo flexure drives Piezo drives can also be used to generate slow and continuous motion of infusion pumps as seen in the animation above. A piezo linear actuator can be directly connected to a piston or a diaphragm for larger extensions or forces. The diaphragm can be integrated with disk-shaped piezo transducers. The small amounts for each pumping cycle ensures high drive frequencies in the 10’s of kilo Hertz range so as to obtain high flow rates. Miniaturized drive mechanisms are required in micro-diaphragm pumps to provide both variable and continuous flow rates. The solid-state effects inside piezoceramic materials when the electric field is changed (Image: PI) High performance piezo-driven diaphragm micropumps
These requirements are addressed by motor drives and piezoceramic transducers, which are known to have a long track record of ruggedness and reliability in optical technologies and semiconductor manufacturing industries. The spectrum extends from simple low-energy drive components to ultrasonic transducers through to ultra-fast actuators and high-precision positioning systems for pumping and valve applications. Motion and positioning devices play an integral role in the life-science and medical engineering fields, fulfilling their many different requirements. Sponsored Content by Physik Instrumente Introduction
0 kommentar(er)
