From Big Medical Encyclopedia

MICROMANIPULATOR — the device intended for holding the procedures and operations over microobjects which are carried out by means of special microtools controlled visually in sight of a microscope. M found broad application in various fields of biology, medicine and equipment. By means of M. in biology and medicine carry out three main types of microhandling works: 1) the mikrurgichesky manipulations which are carried out on the whole cells and concerning only their relative movement; 2) mikrurgichesky operations, or so-called cytosurgical manipulations, to the Crimea belong the operations affecting internal structures of cells and their components, napr, various type of transplantation, a microinjection, microdissection, enucleation, etc. (see. Micrurgy ); 3) microsurgeries, napr, microeye operations, sewing together of small vessels, elektrofiziol. researches using microelectrodes (see. Microsurgery , Microelectrode method of a research ). M found application in the industry for mechanical testing of textile fibers, assemblies of electronic microchains etc. The first M. of modern type were designed a goal. scientist Skhuten (S. L. Schouten, 1899) and amer. microbiologist Barber (M. of A. Barber, 1904). In 1912 S. S. Chakhotin created M. which gave the chance to make intracellular operations. It should be noted works of the fr. scientist P. Fonbrune on improvement of the technique of microhandling researches. The pneumatic M. designed by it widely is applied (with nek-ry modifications) in microbiological practice.

There are two basic groups of M. — as management of movement of microtools (in three possible directions): The m having three screws of management, and M. having one managing lever. The m of the second group, despite complexity of a design in comparison with the first type, has undoubted advantages concerning ease of management and has great handling opportunities. The principle of transfer of movements to M. can be various: mechanical, pneumatic, hydraulic, electric (piezo - and thermoelectric, electromechanical).

Fig. 1. A habit view of the mechanical micromanipulator which is a part of a set of KM-1: 1 — 4 — elements of a positioner (1 — the basis; 2 — micrometer screws; 3 — a little table; 4 — a guide); 5 — 8 — elements of a head of the micromanipulator (5 — nodes of fastening of holders of microtools; 6 — holders of microtools; 7 — screws of length travel of microtools; 8 — screws of the mechanism of movements, managing directors of holders).

At mechanical M. control of microtools is exercised by direct mechanical transfer of movements of managing bodies (micrometer screws or others). Their idiosyncrasy are high precision, stability of situation and a possibility of movement of microtools in big limits. Domestic MM-1 micromanipulators and the mechanical M. which is included in the package of KM-1 (fig. 1) and also M. of Leitz (Germany) and Brikman (USA), etc. are in practice used.

Fig. 2. A habit view of the pneumatic micromanipulator which is included in the package of KM-1: at the left — the control unit (1 — pneumatic cylinders of horizontal movements; 2 — a pneumatic cylinder of vertical movement; 3 — the managing lever; 4 — tubes for transfer of pressure); on the right — the pneumatic head established on a positioner (5 — a head of the micromanipulator; 6 — the holder of the microtool; 7 — a positioner).

At pneumatic and hydraulic M. microtools move by means of the rychazhok located in mutually perpendicular planes and attached to three membrane boxes extending or contracting depending on the size of pressure of the air or liquid given to them. These M. have one managing lever and provide soft and smooth movement of microtools. It is necessary to refer instability to such M.' shortcomings position of microtools in time because of a gas leak or liquid and their thermal expansion in pneumo - or a hydraulic system. The habit view of the pneumatic M. which is included in the package of KM-1 is shown in the figure 2.

Electric M. include all micromanipulators, movement of microtools at to-rykh is carried out due to electrical energy. Piezoelectric M. is similar pneumatic, with only that difference that the role of membrane boxes is carried out here by piezoelectric plates. These M. are convenient in management and allow to make sharp movements of microtools that is absolutely necessary at nek-ry researches, napr, during the piercing of thick covers of cells. In thermoelectric M. movement is made due to change of length of metal cores owing to heating by their electric current. Electromechanical M. — very difficult devices. Management at them manual or automatic, carried out according to the set program.

Often apply the simplified M. intended for specific researches, e.g. M. for movement of microelectrodes at assignment of the potentials of a brain fastening on the most animal.

For nek-ry researches where the accuracy of immersion of the microtool on a certain depth of a body of interest is very important, apply M. with «step» engines — the engines which are carrying out movement by pieces (steps). For implementation of the majority of microhandling works it is necessary microcamera (see), in to-ruyu place a microobject for about conducting manipulations.

Fig. 3. Scheme of a set of KM-1 micromanipulators: 1 — the basis of a set; 2 - microscope; 3 — a positioner; 4 — the mechanism of movements for data of two microtools on one site of an object; 5 — a node of fastening of the holder of the microtool; 6 — a mechanical head with one managing director of the lever; 7 — a piezoelectric head; 8 — the holder with the microtool; 9 — a pneumatic head - 10 — the control unit of the pneumatic micromanipulator; 11 — the operating console of the piezoelectric micromanipulator; 12 — the control unit of the piezoelectric micromanipulator; 13 — the electrical power unit; solid lines on the scheme designated constant connection of irreplaceable parts of a set, dotted — connection of the replaced and removable parts it.

Various devices and devices are a part of modern sets for microhandling works: micromanipulators, microtools, microcameras, microscopes and lighters, photo and movie cameras, a microsmithy, the device for a pulling of capillaries, ultrasonic prefixes, etc. Quite often M. connect to automatic and television devices; at this body the device turns on in a microscope that gives the chance to watch an object and the carried-out microoperations on the television screen. In a domestic set of KM-1 micromanipulators, the scheme to-rogo is submitted in the figure 3, mechanical, piezoelectric microhandling heads, positioners for their fastening and the presetting into position, control units, mechanisms of movement for data of two microtools on one site of an object, etc. enter pneumatic. Depending on the nature of the carried-out works it is possible to establish various microscopes. The design of a set allows depending on requirements of an experiment to easily replace one components with others.

Bibliography: Microhandling methods of experimental microbiology, under the editorship of B. A. Fichte, M., 1977, bibliogr.; Fonbryun P. Methods of micromanipulation, the lane with fr., M., 1951; Khokhlov A. M., Reshetnikov V. I. and I am h and N B. M. Printsip of creation and the description of a set of KM-1 micromanipulators, Cytology, t. 13, No. 4, page 540, 1971; E 1 - In a d of at H. M of Micromanipulators and micromanipulation, Wien, 1963, bibliogr.; To about p and with M. of J. Micromanipulators, principles of design, operation and application, in book: Phys. techn. biol, res., ed. by W. L. Nastuk, v. 5, pt A, p. 191, N. Y. — L., 1964, bibliogr.; To about p and with M. J. a. H and of of i s J. Microsurgery and visible light television, Ann. N. Y. Acad. Sci., v. 97, p. 331, 1962.

A. B. Tsypin, Yu. V. Agibalov.