Abstract:
A micro fluid device in which a plurality of units with fine channel therein are integrally coupled together to bring the fine channels of the units into communication with each other to cause fluid to flow into the fine channels to perform desired unit operations, and at least one of the plurality of units is a temperature controlling unit for controlling the temperature of the fluid, comprises: a heat insulator which has a through hole equal in diameter to the fine channels and is interposed between the temperature controlling unit and an adjacent unit substantially adjacent to the temperature controlling unit; and a positioning mechanism which positions the heat insulator so as to bring the fine channels into communication with the through hole at the time of coupling the units.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a micro fluid device, and in particular, to a micro fluid device with a function to accurately control change in temperature of fluid flowing through a fine channel. 
         [0003]    2. Description of the Related Art 
         [0004]    A micro fluid device with a fine channel has such a superior feature as to enable accurately controlling change in temperature of fluid flowing through a fine channel. And the micro fluid device is used as a device in a micro chemical process where various unit operations such as reaction, mixing, extraction and separation are performed. Unit operations by the micro fluid device require operations in which temperature of reactants is increased to a predetermined degree to accelerate reaction and then to quench to stop the reaction or solution into which solute high in temperature dissolves is quenched to accurately precipitate the solute. In particular, in the case where fine particles are produced by precipitation reaction in which solute is precipitated from solution into which the solute dissolves, it is extremely important to steeply quench the temperature of the solution. 
         [0005]    The accurate control of temperature of fluid which flows through a fine channel requires a small heat transfer between the fine channel and the outside, an accurate change in temperature of fluid (enabling a rapid change in temperature) and a minimum possible dead space in the fine channel where the fluid may retain. 
         [0006]    A micro fluid device provided with a mechanism for controlling temperature is described in, for example, Japanese Patent Application Laid-Open Nos. 2006-61903, 2006-159165 and 2006-326542. Japanese Patent Application Laid-Open Nos. 2006-61903 and 2006-159165 provide a device for covering the periphery of the fine channel with heat insulating materials. Japanese Patent Application Laid-Open No. 2006-326542 discloses a micro fluid device capable of precluding disturbance such as retention of fluid and temperature variation to improve quality of products. 
         [0007]    The micro fluid devices in Japanese Patent Application Laid-Open Nos. 2006-61903 and 2006-159165 cover the periphery of the fine channel with heat insulating materials to enable reducing heat transfer between the fine channel and the outside, however, the micro fluid devices have a drawback in that they cannot rapidly stop reaction or perform precipitation reaction for producing fine particles because no device is provided to accurately change the temperature of the fluid. 
         [0008]    Incidentally, the micro fluid device needs producing by fine processing because it has a fine channel. In this case, the micro fluid device can be more easily produced such that a plurality of units is formed by fine processing, thereafter the units are coupled together to be integrated. Japanese Patent Application Laid-Open No. 2006-326542 discloses an example in which various members forming the micro fluid device are coupled. Coupling portions are coupled with a plurality of tubes or connectors, causing a problem in that a dead space is liable to be formed at a connector portion and the temperature of fluid is liable to be scattered due to a subtle difference in length of the tubes. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention has been made in view of the above situations and has for its object to provide a micro fluid device capable of accurately changing the temperature of fluid flowing through the fine channel and preventing the fluid from being retained at coupling portions even in structure in which a plurality of units is coupled. 
         [0010]    To achieve the above object, a first aspect of the present invention provides a micro fluid device in which a plurality of units with fine channels therein is integrally coupled together to bring the channels into communication with each other to cause fluid to flow into the fine channels to perform desired unit operations, and at least one of the plurality of units is a temperature controlling unit for controlling the temperature of the fluid, comprising: a heat insulator which has a through hole equal in diameter to the fine channels and is interposed between the temperature controlling unit and an adjacent unit substantially adjacent to the temperature controlling unit; and a positioning mechanism which positions the heat insulator so as to bring the fine channels into communication with the through hole at the time of coupling the units. 
         [0011]    Here, “substantially adjacent to” means that, in the case where a temperature detector (a temperature detecting plate), for example, which is not the primary unit of the micro fluid device is interposed between a temperature controlling unit and an adjacent unit, strictly speaking, the temperature controlling unit is not adjacent to the adjacent unit, however, this case is construed as being substantially adjacent. 
         [0012]    According to the first aspect of the present invention, a heat insulator with a through hole which is brought into communication with fine channels formed in the temperature controlling unit and the adjacent unit and is equal in diameter to the fine channels is interposed between the temperature controlling unit which is at least one of a plurality of units and the adjacent unit substantially adjacent to the temperature controlling unit. This effectively insulates heat between the temperature controlling unit and the adjacent unit, so that the temperature of the fluid flowing from the temperature controlling unit to the adjacent unit through the through hole of the heat insulator can be rapidly changed from the temperature of the temperature controlling unit to that of the adjacent unit. That is to say, the temperature can be changed at a steep temperature gradient. 
         [0013]    Incidentally, if two adjacent units different in temperature are thermally isolated from each other and fluid is caused to flow through the two units, the fine channel of one unit is generally coupled to that of the other unit by a coupling pipe or a connector made of SUS material, and so on, which is a thermal conductor. In this case, however, heat is conducted from the one unit to the other through the coupling pipe or the connector, so that a steep temperature gradient cannot be obtained, which fails to rapidly change the temperature of the fluid. 
         [0014]    According to a second aspect, in the micro fluid device according to the first aspect of the present invention, the fine channel and the through hole are 5 mm or less in diameter. 
         [0015]    The diameter of the fine channel and the through hole is preferably 5 mm or less at which the fluid flows as laminar flow, more preferably 1 mm or less, further preferably 500 μm or less to accurately control the temperature of the fluid flowing through the fine channel and the through hole. Incidentally, although a lower limit is not specified, a channel width which can be formed by a microfabrication becomes a lower limit. 
         [0016]    According to a third aspect, in the micro fluid device according to the first or the second aspect of the present invention, the temperature controlling unit comprises two units of a heating unit and a cooling unit, and the heat insulator is substantially interposed between the heating unit and the cooling unit. 
         [0017]    As described in the first aspect, the above phrase “substantially interposed” includes the case where a member such as the temperature detector which is not included in the units is interposed therebetween. 
         [0018]    The third aspect describes a preferable embodiment of a relationship between the temperature controlling unit and the heat insulator. The heat insulator is preferably interposed between the heating unit and the cooling unit. This enables the fluid to be rapidly cooled or heated from the temperature of the heating unit to that of the cooling unit at a steep temperature gradient while the fluid is passing through the heat insulator. 
         [0019]    According to a fourth aspect, in the micro fluid device according to any one of the first to the third aspects of the present invention, the heat conduction coefficient of the heat insulator is 2 (W/S/K) or less. 
         [0020]    This is because the heat insulator with a heat conduction coefficient 2 (W/S/K) or less can be decreased in thickness. The reason is that, although the increase of thickness of the heat insulator can heighten an insulation effectiveness, the increase of thickness also lengthens the through hole, resulting in the retention of the fluid. 
         [0021]    According to a fifth aspect, in the micro fluid device according to any one of the first to the fourth aspects of the present invention, the heat insulator is 0.5 mm or more to 50 mm or less in thickness. 
         [0022]    There is a considerable relationship between the thickness of the heat insulator and the heat conduction coefficient, however, an excessively thick heat insulator involves a difficulty in workability of the fine channel, obliging the diameter of the channel to be increased, which results in the retention of the fluid. On the other hand, an excessively thin heat insulator does not provide a sufficient insulation effectiveness. Consequently, the heat insulator is preferably 0.5 mm or more to 50 mm or less in thickness. 
         [0023]    According to a sixth aspect, in the micro fluid device according to any one of the first to the fifth aspects of the present invention, the positioning mechanism performs positioning by fitting a projecting mating part provided on the heat insulator into a recessed mating part provided in the temperature controlling unit, and the projecting mating part is formed to be a point symmetry with respect to the through hole. 
         [0024]    According to the sixth aspect of the present invention, the positioning mechanism is formed such that the projecting mating part formed on the heat insulator is fitted into the recessed mating part formed in the temperature controlling unit, and the projecting mating part is formed to be a point symmetry with respect to the through hole. This forms the projecting mating part thermally symmetrical with regard to the through hole as a center, so that the position of the through hole of the heat insulator which is positioned with respect to the temperature controlling unit is not shifted even if the heat insulator thermally expands or shrinks. 
         [0025]    According to a seventh aspect, in the micro fluid device according to any one of the first to the sixth aspects of the present invention, the through hole of the heat insulator is subjected to surface treatment to improve durability under and affinity for the fluid. 
         [0026]    According to the seventh aspect, subjecting the inner surface of the through hole of the heat insulator to surface treatment to improve affinity for the fluid allows preventing bubbles in liquid from being retained in the fine channel when the liquid is caused to flow through the fine channel, for example. In addition, subjecting the inner surface of the through hole of the heat insulator to surface treatment to improve durability under the fluid allows maintaining smoothness on the fine channel to smooth the flow of the fluid, preventing the fluid from being retained. Incidentally, a surface treatment layer formed by the surface treatment to which the through hole is subjected is preferable superior in heat isolation. This is because the surface treatment layer is prevented from transferring heat between the temperature controlling unit and the adjacent unit. 
         [0027]    According to an eighth aspect, in the micro fluid device according to any one of the first to the seventh aspects of the present invention, the heat insulator comprises a sealing member for preventing the fluid from leaking from the coupling portions between the channels and the through hole. 
         [0028]    According to the eighth aspect, providing the sealing member on the heat insulator enables surely preventing the fluid from leaking even if the heat insulator thermally expands and shrinks. 
         [0029]    According to a ninth aspect, the micro fluid device according to any one of the first to the eighth aspects of the present invention further comprises a temperature detector with a temperature detecting function which is interposed between the temperature controlling unit and the heat insulator, and has a communicating hole for bring the channel into communication with the through hole. 
         [0030]    Providing the temperature detector between the temperature controlling unit and the heat insulator permits accurately detecting change in temperature while the fluid flows from the temperature controlling unit to the adjacent unit through the heat insulator. 
         [0031]    According to the present invention, the micro fluid device is capable of accurately changing the temperature of fluid flowing through the fine channel and preventing the fluid from being retained at coupling portions even in structure in which a plurality of units is coupled. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1  is an exploded view illustrating the general configuration of the micro fluid device according to an embodiment of the present invention; 
           [0033]      FIG. 2  is a cross section of the principal part in  FIG. 1 ; 
           [0034]      FIG. 3  is a cross section of the principal part excluding a temperature detector in  FIG. 2 ; 
           [0035]      FIG. 4  is a perspective view illustrating one embodiment of a positioning mechanism of an heat insulator; 
           [0036]      FIG. 5  is a perspective view illustrating another embodiment of positioning mechanism of the heat insulator; 
           [0037]      FIG. 6  is a perspective view illustrating further another embodiment of positioning mechanism of the heat insulator; and 
           [0038]      FIG. 7  is a chart describing the action and effect of the micro fluid device  10  according to the embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0039]    A preferable embodiment of a micro fluid device according to the present invention is described in detail with reference to the accompanied drawings. 
         [0040]      FIG. 1  is an exploded view illustrating one example of the general configuration of a micro fluid device  10  according to an embodiment of the present invention.  FIG. 2  is a cross section of the principal part of the micro fluid device according to an embodiment of the present invention. 
         [0041]    As illustrated in  FIGS. 1 and 2 , the micro fluid device  10  according to the embodiment of the present invention mainly includes a fluid supplying unit  12 , a heating unit  14  (or, a temperature controlling unit), a heat insulator (heat insulating plate)  16 , a cooling unit  18  (or, a temperature controlling unit) and a fluid discharging unit  20 . Temperature detectors (temperature detecting plates)  22  and  24  are provided between the heating unit  14  and the heat insulator  16  and between the heat insulator  16  and the cooling unit  18  respectively. The units  12 ,  14 ,  18  and  20 , the heat insulator  16  and the temperature detectors  22  and  24  are integrally assembled in the above order and fastened with a bolt, and so on (not shown), to form the micro fluid device  10 . 
         [0042]    As the fluid A supplied to the micro fluid device  10 , there may used liquid or gas, which is selected according to target unit operations such as reaction, mixing, extraction and separation. 
         [0043]    The fluid supplying unit  12  is formed in a disk shape and a through hole drilled at the center of the disk forms an inlet channel  12 A (or, a fine channel) of the fluid A. A disk-shaped projection (refer to the projection  20 B of the fluid discharging unit) is formed on the face of the fluid supplying unit  12  on the side of the heating unit, and the projection is fit into one end of a cylindrical casing  14 A of the heating unit  14 . 
         [0044]    The heating unit  14  mainly includes the cylindrical casing  14 A, a small-diameter pipe  14 D through which the fluid A flows and a heating medium X for heating the fluid A. That is to say, the spiral pipe  14 D is disposed in the casing  14 A. The one end of the pipe  14 D is connected to the inlet channel  12 A of the fluid supplying unit  12 . The other end of the pipe  14 D is connected to a communicating hole  22 A drilled at the center of the disk-shaped temperature detector  22 . As the temperature detectors  22  and  24 , there may be preferably used a thermo-couple detector, for example, however, a detector is not limited to the thermo-couple detector. An inlet  14 B for the heating medium X is formed on the peripheral surface of the casing  14 A on the side of one end thereof and an outlet  14 C for the heating medium X is formed on the peripheral surface of the casing  14 A on the side of the other end thereof. Although the spiral pipe is used in the present embodiment, a pipe is not limited to this, but the pipe may be linear or meandering. In short, it is important for the heating unit  14  to enable the fluid A to be effectively heated to a desired temperature. 
         [0045]    The heat insulator  16  is formed in a disk shape and a through hole  16 A is made at the center of the disk. As described later, a positioning mechanism provided on the heat insulator  16  performs positioning so that the shaft center of the through hole  16 A coincides with that of the communicating hole  22 A of the foregoing temperature detector  22 . The heat conduction coefficient of the heat insulator  16  is preferably 2 (W/S/K) or less and more preferably 0.5 (W/S/K) or less. The heat insulator  16  is preferably 0.5 mm or more to 50 mm or less in thickness and more preferably 3 mm or more to 10 mm or less. As a material for the heat insulator  16 , there may be preferably used resin materials such as, for example, polyimide resin, acrylic resin and Teflon (registered trademark) and ceramic material such as alumina and glass. In order to decrease the heat conduction coefficient of the heat insulator  16 , the heat insulator  16  may be hollow, the air in the hollow may be evacuated therefrom to create a vacuum or the hollow may be filled with gas small in heat conduction coefficient. What is important is that the through hole  16 A formed in the heat insulator  16  is thermally separated by the pipe  14 D of the heating unit  14  and the pipe  18 D of the cooling unit  18 . 
         [0046]    The through hole  16 A in the heat insulator  16  is preferably subjected to surface treatment to improve durability under or affinity for the fluid A. In this case, as described above, it is important for the heat insulator  16  to be thermally separated. It is desirable that a surface treatment layer itself is also small in heat transfer similarly to the heat insulator  16 . As for the surface treatment, if the heat insulator  16  is made of resin, for example, the surface treatment layer small in heat transfer as in glass coating and ceramics coating is preferably formed. This is because the heat of the heating unit  14  and the cooling unit  18  is transferred to each other through the surface treatment layer in the case where the heat insulator  16  is directly interposed between the heating unit  14  and the cooling unit  18  without using the temperature detectors  22  and  24  as illustrated in  FIG. 3 , because the through hole  16 A on which the surface treatment layer is formed is brought into contact with the pipes  14 D and  18 D made of, for example, “steel use stainless” (SUS) disposed in the heating unit  14  and the cooling unit  18 . For this reason, if the through hole  16 A is subjected to the surface treatment of SUS coating or Ti coating, it is preferable that the surface treatment layer is formed of a thin film which is resistive to heat transfer through the surface treatment layer or the surface treatment layer is prevented from touching the pipes  14 D and  18 D. 
         [0047]    In addition, an O-ring  23  is interposed between the faces of the heat insulator  16  and the temperature detector  22  which are coupled together to seal against leakage of the fluid A from the coupling portion between the through hole  16 A of the heat insulator  16  and the communicating hole  22 A of the temperature detector  22 . 
         [0048]    The cooling unit  18  is the same in structure as the above heating unit  14 . That is to say, the small-diameter spiral pipe  18 D (fine channel) is disposed in the casing  18 A. The one end of the pipe  18 D is connected to the outlet channel  20 A, described later, of the discharging unit  20 . The other end of the pipe  18 D is connected to a communicating hole  24 A drilled at the center of the disk-shaped temperature detector  24 . An inlet  18 B for a cooling medium Y is formed on the peripheral surface of the casing  18 A on the side of one end thereof and an outlet  18 C for the cooling medium Y is formed on the peripheral surface of the casing  18 A on the side of the other end thereof. The temperature detector  24  is the same as in the above description. 
         [0049]    The fluid discharging unit  20  is formed in a disk shape and a through hole drilled at the center of the disk forms the inlet channel  12 A (fine channel) for the fluid A. A disk-shaped projection  20 B is formed on the face of the fluid discharging unit  20  on the side of the heating unit, and the projection  20 B is fit into one end of the cylindrical casing  18 A of the cooling unit  18 . 
         [0050]    The diameter of the inlet channel  12 A of the fluid supplying unit  12 , the pipe  14 D of the heating unit  14 , the communicating holes  22 A and  24 A of the first and the second temperature detectors  22  and  24 , the through hole  16 A of the heat insulator  16 , the pipe  18 D of the cooling unit  18  and the outlet channel  20 D of the fluid discharging unit  20  is preferably 5 mm or less, more preferably 1 mm or less, particularly preferably 500 μm or less. 
         [0051]      FIGS. 4 to 6  are schematic views of a positioning mechanism provided on the heat insulator  16 . 
         [0052]    The positioning mechanism illustrated in  FIG. 4  is one in which circular projections  16 B centered about the through hole  16 A are formed on both faces of the heat insulator  16  formed in a disk shape. The circular projections  16 B are fit into circular recesses  22 B and  24 B formed and centered about the communicating holes  22 A and  24 A on the temperature detectors  22  and  24 . This causes the shaft center  26  of the through hole  16 A of the heat insulator  16  to coincide with that of the communicating holes  22 A and  24 A of the temperature detectors  22  and  24  (refer to  FIGS. 2 and 3 ). 
         [0053]    The positioning mechanism illustrated in  FIG. 5  is one in which a plurality of spike-type projections  16 C is formed at equally spaced intervals at positions equal from the through hole  16 A on both faces of the heat insulator  16  formed in a disk shape. The spike-type projections  16 C are fit into a plurality of spike-type recesses (not shown) formed at equally spaced intervals at positions equal from the communicating holes  22 A and  24 A on the faces of the temperature detectors  22  and  24 . The spike-type projections  16 C positionally correspond to the spike-type recesses, causing the shaft center  26  of the through hole  16 A of the heat insulator  16  to coincide with that of the communicating holes  22 A and  24 A of the temperature detectors  22  and  24 . 
         [0054]    The positioning mechanism illustrated in  FIG. 6  is provided with a cylindrical sleeve  28  whose bore diameter is equal to the outer periphery of the heat insulator  16  and the temperature detectors  22  and  24  and the heat insulator  16  and the temperature detectors  22  and  24  are fit into the sleeve  28 , thereby regulating the outer periphery of the heat insulator  16  and the temperature detectors  22  and  24 . This causes the shaft center  26  of the through hole  16 A of the heat insulator  16  to coincide with that of the communicating holes  22 A and  24 A of the temperature detectors  22  and  24 . 
         [0055]    The action of the micro fluid device  10  thus formed is described below. 
         [0056]    The fluid A supplied to the inlet channel  12 A of the fluid supplying unit  12  is heated by the heating medium X while flowing through the pipe  14 D of the fine channel in the heating unit  14 , thereby the temperature of the fluid A is accurately raised to a desired point. The temperature detector  22  measures whether the temperature of the fluid A is correctly raised to the desired point. 
         [0057]    The fluid A the temperature of which is raised to the desired point flows into the pipe  18 D of the cooling unit  18  through the through hole  16 A of the heat insulator  16 . The fluid A having flowed into the pipe  18 D is quenched by the cooling medium Y in the cooling unit  18 . The temperature detector  24  measures whether the fluid A is correctly cooled to the desired temperature. 
         [0058]    The heating unit  14  and the cooling unit  18  are thermally insulated by the heat insulator  16  while the fluid A is quenched. The pipe  14 D of the heating unit  14  is thermally separated from the pipe  18 D of the cooling unit  18  by the through hole  16 A of the heat insulator  16 . As illustrated in  FIG. 7 , while passing through the through hole  16 A of the heat insulator  16 , the fluid A is quenched from a heating temperature of A° C. in the heating unit  14  to a cooling temperature of B° C. in the cooling unit  18  at a steep temperature gradient (as indicated by the solid line in  FIG. 7 ). The temperature gradient indicated by the dotted line in  FIG. 7  is obtained in the case where the pipe  14 D of the heating unit  14  is coupled to the pipe  18 D of the cooling unit  18  by a connector made of SUS material which has high heat conduction. This cannot provide a steep temperature gradient. 
         [0059]    The fluid A of which the temperature is cooled to the desired point by the cooling unit  18  is discharged outside from the outlet channel  20 A of the fluid discharging unit  20 . 
         [0060]    In the present embodiment, although the heating medium X and the cooling medium Y are flowed into the heating unit  14  and the cooling unit  18  respectively to control heat, an electric heater or a Peltier element may be used. In addition, in the present embodiment, each unit of the micro fluid device  10  is disk-shaped and cylindrical to obtain a thermal symmetry, a completely thermal symmetry is not always required to be maintained depending on kinds of fluid flowing through the pipe and a degree of demand for a temperature gradient. For instance, there may be used a rectangular parallelepiped unit. 
       Embodiment 
       [0061]    The present embodiment is such that the micro fluid device  10  of the present invention illustrated in  FIG. 1  is applied to a process for producing fine particle dispersion liquid (emulsion dispersion material) using a phase-inversion temperature emulsification reaction. In the phase-inversion temperature emulsification reaction, the fluid A is accurately heated to a predetermined temperature and then quenched to precipitate solute, thereby obtaining fine particle dispersion liquid. 
         [0062]    As fluid supplied to the micro fluid device  10 , the liquid A was used in which water is mixed with cyclohexane at a ratio of water of 54.6% by mass to cyclohexane of 36.4% by mass and then mixed with polyoxyethylene (POE) of 9% by mass. It is known that the liquid A develops a phase-inversion temperature emulsification phenomenon and the balance of hydrophilicity and lipophilic of POE inverts at a phase-inversion temperature of 60° C. to 65° C., and the liquid A becomes a system in which cyclohexane is dispersed in water at a temperature of 60° C. or less, however, the liquid A becomes a system in which water is dispersed in cyclohexane at a temperature of 65° C. or higher. 
         [0063]    In the present embodiment, the diameter φ of the pipe  14 D, the through hole  16 A and the communicating holes  22 A and  24 A is set to 300 μm and the thickness of the heat insulator  16  is set to 15 mm. The diameter is not restricted if a heat exchange rate (thermal gradient) on the heat insulator  16  reaches a target. The diameter φ is preferably 5 mm or less at which the liquid A (fluid) generally flows as laminar flow, and is more preferably 1 mm or less. 
         [0064]    The flow rate of the liquid A was set to 0.1 mL/min. The temperature of the heating medium X in the heating unit  14  was set to 85° C. and the temperature of the cooling medium Y in the cooling unit  18  was set to 5° C. Temperature was measured at the front and rear of the heat insulator  16  by the temperature detectors  22  and  24  (thermocouples were used) attached to the front and rear of the heat insulator  16 . 
         [0065]    According to the above micro fluid device  10 , the liquid A which was heated to a phase-inversion temperature or higher by the heating unit  14  and was in a state where water is dispersed in cyclohexane was quenched at a cooling rate of 1000° C./sec or more while passing through the 15-mm thick heat insulator  16 . This lowered the temperature of the liquid A to the phase-inversion point or less, and the liquid A becomes the system in which cyclohexane is finely dispersed in the water. 
         [0066]    As a result, the diameters of fine particles in the liquid A varied from several μm to 100 μm before the fine particle passed through the micro fluid device  10  of the present invention. On the other hand, after the liquid A was caused to pass through the micro fluid device  10 , a fine emulsified dispersion with good monodisperse in which the diameters of fine particles are 2 μm to 3 μm could be obtained.