Cell sorting is a key process in modern medicine, and it has a wide range of applications in medical technology, biotechnology, and research. It serves as an instrument for the detailed investigation of specific cell types and their complex functionalities based on their size, shape, and prior marking with fluorescent dyes. So-called flow cytometers, usually coupled with a downstream sorting function, are used to continuously analyze cells in microfluidic channels. This technology enables the selective enrichment of specific cell types from heterogeneous cell populations such as blood or tissue samples. Piezoceramic components form the core of this innovative technology which makes use of two possible methods:
Using a Pressure Pulse Generated by Piezoelectricity to Sort Cells
Piezoceramic >> bending actuators or stack actuators enable the sorting of both cells and particles by using highly dynamic pressure pulses generated by piezoelectricity. For example, a bending membrane can transmit these pulses on a liquid inside the channels of a lab-on-a-chip system, thereby controlling the individual flow direction of particles. Systems that feature >> piezoelectric stack actuators are able to achieve extremely high rates of sorting. These actuators press on a membrane to trigger the hydrodynamic sorting pulse. Arrays of such actuators enable complex sorting patterns with multiple channels.
Using Acoustic Waves to Sort Cells
Cells can be sorted acoustophoretically and without contact based on their different physical properties such as size or density using acoustic standing waves, for example. These waves are generated by piezoelectric transducers and cause cells to react differently to changes in pressure, creating a continuous microfluidic sorting function. So-called acoustical tweezers use soundwaves to precisely control the position and movement of particles or cells by moving acoustic pressure nodes in a controlled manner. These technologies are primarily used to move individual, microscopically small objects precisely and without direct contract.
