Micro-... what?

 Get to know the generic terms, subdivisions and some special terminology of MST in practice.

Generic Terms

Microtechnology = generic term for all technologies and procedures concerning the production and application of any structures at the scale of micrometers.
The subdivisions of microtechnology are hard to separate neatly from each other, because they overlap and are often applied in combination. Therefore the term micro systems technology emerged. 

Micro systems technology = short form: MST; collective name for the combined realization of elements originating from the different microtechnological subdivisions as micro electronics, micro mechanics or micro fluidics.

Subdivisions

Microfluidics = discipline of transport, dosing, mixing and all other methods of handling liquids and gases (= fluids) in micro dimensions.
Pumps, filters, valves and other elements known from the "big world" are used in miniature variants. But fluids behave differently in these small dimensions, which poses a central challenge to microfluidics and same time opens up truly specific possibilities. For example two different fluids can be made to flow parallel but seperately in a so called laminar stream. The lack of turbulences in such streams allows for completely controlled diffusion processes. 

Digital microfluidics = whenever defined droplets are moved and controlled instead of continuous streams, the processes can be considerered part of digital microfluidics. By the technology of electrowetting, for example, binary states of single droplets can be triggered directly and the droplets can be moved freely on a surface without any channel structure. 

Micromechanics = technology concerned with mechanical components with micro scale dimensions. The discipline of mechanics generally studies force effects on motion and deformation of bodies.
Purely mechanical elements in microtechnology for example are micogrippers allowing precise surgical access to even the smallest fibers of tissue. 

Microactuation = micro variant of actuation, a subdivision of mechanics which is specifically concerned with the generation of motion or deformation. Microactuation components (actuators) with micro scale dimensions transfer electronic signals into motions of different kinds.
A good example for a micro actuator is a piezo diaphragm as used in micropumps. Its up- and downstrokes stimulated by an electronic signal set liquids in motion. The piezoelectric diaphragm pumps can itself serve as an actuator, when for example it is used to control the volume of flexible tubings that again adjust the position of larger components. Such designs are also referred to as "fluidic muscles".

Applications, Equipment and Technologies

Bonding = joining technique used to connect two materials impermeably to fluids without an additional adhesive layer. This can be done for example by surface-fusing and compressing the materials under high pressure.

Electrowetting = principle of deforming and moving single droplets of liquid by modification of their surface tension using an electrical field. The imaginable applications of electrowetting are numerous. Some examples are Lab-on-a-Chip-Systems, fluidic lenses or displays with liquid pixels.

Excimerlaser = type of laser. The light of an excimerlaser can disintegrate molecular bonds coldly, without any heat being generated. The material processed is ablated in extremely fine layers, so that the procedure is especially suited for any structuring in smallest dimensions. This precise and "gentle" type of laser is the one used for example in corneal surgery.

Fiberlaser = type of laser used among other applications for the welding of polymer substrates with high performance. It allows for a particularly material saving and strong joining of smallest elements to microtechnological components.

Fluidic Muscles = mechanical actuators set in motion by being filled with liquids or gases. Chambers with elastic skins for example can be constructed in such way that they become broader when they are filled and at the same time shorten. Thus they exert tractive forces onto other components connected to them. Using this principle, as an example, adjustment elements can be built that do not require a classical motor.

Lab-on-a-Chip = "Laboratory on a chip"; mobile analysis unit serving to examine extremely small samples for example of body fluids. A Lab-on-a-Chip is installed on a small plastic card or glass and runs complex laboratory processes as transporting, mixing and isolating of liquids. Thus the samples are prepared to be screened by different methods of detection generating results ready for analysis right on the spot.

Nd:YAG-Laser = solid-state laser named after its active laser medium: A crystal of Neodymium-doped yttrium aluminium garnet. The Nd:YAG is used for marking and welding.

Piezo electric diaphragm pump = pump with an actuator consisting of a piezo mounted to a membrane. When a voltage is being applied and varied, the piezo deforms in such way that the membrane lifts up and lowers again. Liquids or gases being in the pump chamber below the membrane thus are squeezed out and sucked in. Valves on both sides of the chamber define the direction of the flow. The alternation of filling and emptying the chamber forms continuous pumping cycles of which several hundreds can be completed every second.