Patent Publication Number: US-2022213875-A1

Title: Soft actuator having cooler, wearable robot having the same, massage device having the same, and method for controlling the same

Description:
BACKGROUND 
     1. Field of Disclosure 
     The present disclosure of invention relates to a soft actuator having a cooler, a wearable robot having the soft actuator, a massage device having the soft actuator, and a method for controlling the soft actuator, and more specifically the present disclosure of inventions relates to a soft actuator having a cooler for enhancing relaxation response, a wearable robot having the soft actuator, a massage device having the soft actuator, and a method for controlling the soft actuator. 
     2. Description of Related Technology 
     Generally, industrial workers, unloading workers, package delivers and so on, pick up heavy weight objects repeatedly and moves the objects repeatedly. 
     Those kinds of working need a lot of workers or additional equipment such as a heavy equipment, a crane, a pulley and so on. In addition, when the workers work the working directly, worker&#39;s fatigue is increased and working efficiency is decreased, and furthermore, industrial accidents such as a musculoskeletal system injury may be caused due to the high working intensity. Thus, avoidance may be caused on those kinds of workings, and relatively larger area of moving space or equipment space is necessary when the additional equipment is used, so that the use of the additional equipment may be restricted. 
     Thus, wearable strength aids are necessary for releasing a standing up action with picking up the heavy weight object repeatedly, or releasing an enduring action with having the heavy weight object. 
     Recently, the wearable strength aids are normally attached to a side of an arm or a leg, and are operated using a motor and a frame. 
     However, those kinds of wearable strength aids need the motor for driving the frame, and the weight is increased and the structure is not flexible, so that those aids cause difficulty in natural movement and also cause uncomfortable to wear. 
     Thus, a wearable robot (strength-enhancing clothing) having a light weight, not impeding body movement with being attached to a similar position of human muscle, and increasing responsiveness of various kinds of operations, should be developed. 
     To meet the above needs, a fabric flexible actuator and a strength assisting device having the fabric flexible actuator, in which a shape memory alloy spring is used, was developed. However, the shape memory alloy spring depends on a natural cooling in controlling a temperature, and thus the cooling speed is relatively slow. Thus, the wearable robot (strength assisting device) normally has a relatively slow relaxation rate. 
     SUMMARY 
     The present invention is developed to solve the above-mentioned problems of the related arts. 
     The present invention provides a soft actuator, capable of not impeding body movement with being attached to a similar positon of human muscle, increasing responsiveness of various kinds of operations, and increasing cooling speed of a shape memory alloy spring with using the shape memory alloy spring. 
     In addition, the present invention also provides a wearable robot having the soft actuator. 
     In addition, the present invention also provides a massage device having the soft actuator. 
     In addition, the present invention also provides a method for controlling soft actuator. 
     According to an example embodiment, soft actuator includes a heat reaction member, a cooling part and a controller. The heat reaction member is configured to be contracted or relaxed according to a temperature change. The cooling part includes a cooling surface disposed at the heat reaction member, and a heating surface disposed opposite to the cooling surface. The controller is configured to control a power supply part so that a power is blocked to be supplied to the heat reaction member and the power is supplied to the cooling part, when the heat reaction member is changed to be a relaxation state. 
     In an example, the cooling surface and the heating surface may be respectively cooled and heated, when the power is supplied to the cooling part. 
     In an example, the cooling part may be a flexible thermoelectric element, and a body of the soft actuator may have a material which is contracted or relaxed according as the heat reaction member is contracted or relaxed. 
     In an example, the soft actuator may further include a body configured to receive at least a portion of the heat reaction member inside of the body. The body and the cooling part may be connected with each other. 
     In an example, the cooling part may be connected to the body so that the cooling part is disposed inside of or outside of the heat reaction member along a longitudinal direction of the heat reaction member. 
     In an example, the cooling part may include first and second cooling parts facing each other with disposing the heat reaction member between the first and the second cooling parts. 
     According to another example embodiment, a soft actuator includes a heat reaction member, a cooling part and a controller. The heat reaction member is configured to be contracted or relaxed according to a temperature change. The cooling part is configured to cool down the heat reaction member forcibly. The controller is configured to control a power supply part so that a power is blocked to be supplied to the heat reaction member and the power is supplied to the cooling part, when the heat reaction member is changed to be a relaxation state. The cooling part sprays a cooling air to make direct contact with the heat reaction member, for increasing a relaxation speed of the heat reaction member, when the heat reaction member is in a relaxation state. 
     In an example, the soft actuator may further include a body configured to receive at least a portion of the heat reaction member inside of the body. 
     In an example, the cooling part may include an inlet flow configured to flow the cooling air inside of the body, and a discharge flow configured to flow the cooling air outside of the body. 
     In an example, the heat reaction member may be arranged along a direction inside of the body, and an inlet portion of the inlet flow for the cooling air may be formed as an opening heading for the direction. 
     In an example, the inlet flow for the cooling air may be formed at a first side of the body, and the discharge flow for the cooling air may be formed at a second side of the body. 
     In an example, the heat reaction member may be arranged along a direction inside of the body, and the inlet flow for the cooling air may have a micro inlet flow which is extended from the inlet flow along the direction. 
     In an example, the micro inlet flow may have a length shorter than that of the heat reaction member in the relaxation state. 
     In an example, each of the micro inlet flow and the heat reaction member may be a plural, and each of the plurality of micro inlet flows may be disposed between the plurality of heat reaction members to prevent the heat reaction members adjacent to each other from making contact with each other. 
     In an example, an inlet portion may be formed as a plural at the micro inlet flow, and at least one inlet portion may have an opening substantially perpendicular to the direction along which the heat reaction member is arranged. 
     According to still another example embodiment, a wearable robot includes a cloth body and the soft actuator configured to be connected to the cloth body. A first side of the soft actuator is disposed at a first body fixing part, and a second side of the soft actuator is disposed at a second body fixing part which is disposed opposite to the first body fixing part with respect to a position corresponding to a joint. 
     In an example, the wearable robot may further include a sensing part configured to measure a movement of a wearer. Here, the controller may control a power supply part so that a power is blocked to be supplied to the heat reaction member and the power is supplied to the cooling part, when the sensing part measures a relaxation action of the wearer. 
     According to still another example embodiment, a massage device includes an elastic band and the soft actuator configured to be connected to the elastic band. 
     According to still another example embodiment, in a method for controlling a soft actuator, a power supply part is controlled so that a power is blocked to be supplied to a heat reaction member and the power is supplied to a cooling part, when the heat reaction member is changed to be a relaxation state. Here, the soft actuator includes a heat reaction member, a cooling part and a controller. The heat reaction member is configured to be contracted or relaxed according to a temperature change. The cooling part includes a cooling surface disposed at the heat reaction member, and a heating surface disposed opposite to the cooling surface. The controller is configured to control a power supply part so that a power is blocked to be supplied to the heat reaction member and the power is supplied to the cooling part, when the heat reaction member is changed to be a relaxation state. 
     In an example, in the method, the power supply part may be controlled so that the power is blocked to be supplied to the cooling part, when the heat reaction member reaches a maximum relaxation state. 
     In an example, in the method, the power supply part may be controlled so that the power is supplied to the heat reaction member, when the heat reaction member is changed to be a contraction state. 
     According to still another example embodiment, in a method for controlling a soft actuator, a cooling air is sprayed to make direct contact with a heat reaction member, for increasing a relaxation speed of the heat reaction member, when the heat reaction member is in a relaxation state. Here, a soft actuator includes a heat reaction member, a cooling part and a controller. The heat reaction member is configured to be contracted or relaxed according to a temperature change. The cooling part is configured to cool down the heat reaction member forcibly. The controller is configured to control a power supply part so that a power is blocked to be supplied to the heat reaction member and the power is supplied to the cooling part, when the heat reaction member is changed to be a relaxation state. The cooling part sprays a cooling air to make direct contact with the heat reaction member, for increasing a relaxation speed of the heat reaction member, when the heat reaction member is in a relaxation state. 
     In an example, the cooling air may be sprayed to be parallel with or perpendicular to a direction along which the heat reaction member is arranged. 
     According to the present example embodiments, a fabric type soft actuator having a cooler, in which a shape memory alloy spring is used and the cooler controls a temperature of the shape memory alloy spring, a wearable robot having the soft actuator, and a massage device having the soft actuator are provided. 
     Here, the shape memory alloy spring has a relatively large power density of a shape memory alloy wire, and also generates a relatively larger displacement (for example, about several hundred %), so that the soft actuator may be manufactured as a small, light and noiseless wearable fabric type soft actuator. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a structural view illustrating a soft actuator according to an example embodiment of the present invention; 
         FIG. 2  is a side view illustrating an example of the soft actuator of  FIG. 1 ; 
         FIG. 3  is a side view illustrating another example of the soft actuator of  FIG. 1 ; 
         FIG. 4A  is a plan view illustrating an example contraction operation of the soft actuator of  FIG. 1 , and  FIG. 4B  is a plan view illustrating an example relaxation operation of the soft actuator of  FIG. 1 ; 
         FIG. 5A  is a plan view illustrating another example contraction operation of the soft actuator of  FIG. 1 , and  FIG. 5B  is a plan view illustrating another example relaxation operation of the soft actuator of  FIG. 1 ; 
         FIG. 6  is a structural view illustrating a soft actuator according to another example embodiment of the present invention; 
         FIG. 7A  and  FIG. 7B  are structural views illustrating another examples of the soft actuator of  FIG. 6 ; 
         FIG. 8A ,  FIG. 8B ,  FIG. 8C  and  FIG. 8D  are plan views illustrating contraction and relaxation operations of the soft actuator of  FIG. 6 ; 
         FIG. 9A ,  FIG. 9B ,  FIG. 9C  and  FIG. 9D  are plan views illustrating contraction and relaxation operations of the soft actuators of  FIG. 7A  and  FIG. 7B ; 
         FIG. 10  is a structural view illustrating a wearable robot having the soft actuator of  FIG. 1 ; 
         FIG. 11A  and  FIG. 11B  are example operating views illustrating an operation of the wearable robot of  FIG. 10 ; 
         FIG. 12  is a structural view illustrating a massage device having the soft actuator of  FIG. 1 ; and 
         FIG. 13A ,  FIG. 13B ,  FIG. 14A  and  FIG. 14B  are example operating views illustrating an operation of the massage device of  FIG. 12 . 
     
    
    
     DETAILED DESCRIPTION 
     The invention is described more fully hereinafter with Reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. 
     It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention. 
     Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. 
     It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
     It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     The invention is described more fully hereinafter with Reference to the accompanying drawings, in which embodiments of the invention are shown. 
       FIG. 1  is a structural view illustrating a soft actuator according to an example embodiment of the present invention.  FIG. 2  is a side view illustrating an example of the soft actuator of  FIG. 1 .  FIG. 3  is a side view illustrating another example of the soft actuator of  FIG. 1 . 
     Referring to  FIG. 1 , the soft actuator  10  according to the present example embodiment includes a heat reaction member  100 , a cooling part  200  and a controller  300 . 
     Here, the soft actuator  10  may be manufactured to be a cloth type. 
     The heat reaction member  100  extends along a direction D 1 , and is contracted or relaxed according to a change of temperature. For example, when electricity is supplied, the heat reaction member  100  may be contracted along the direction D 1 , in reaction to a heat generated by the electricity. Alternatively, when the supply of the electricity is stopped, the heat reaction member  100  may be relaxed along the direction D 1 , since the temperature due to the heat is decreased. 
     The heat reaction member  100  may be a shape memory alloy material which is reacted to the heat. For example, the heat reaction member  100  may include a shape memory alloy wire or a shape memory alloy spring. 
     Alternatively, except for the shape memory alloy material, the heat reaction member  100  may include various kinds of heat reaction materials such as a shape memory resin, a shape memory polymer (SMP), a carbon nanotube, polyethylene, polyamide, nylon and so on. 
     The heat reaction member  100  is formed as a plurality of bundles, and here, a plurality of bundles of heat reaction members is disposed in parallel with each other. 
     In the plurality of the heat reaction members, a first portion  110   a  of a first side, a second portion  110   b  of the first side, a first portion  120   a  of a second side, and a second portion  120   b  of the second side are connected with each other. In addition, the first portion  120   a  of the second side and the second portion  120   b  of the second side are connected to each other. Thus, a current may flow in order of the first portion  110   a  of the first side, the first portion  120   a  of the second side, the second portion  120   b  of the second side, and the second portion  110   b  of the first side, or in order of an opposite to the order mentioned above. 
     The heat reaction member  100  is received by a body  410  and  420 , and the body is formed to cover the heat reaction member  100  entirely. 
     A first fixing portion  510  and a second fixing portion  520  are respectively disposed at the first side of the body and the second side of the body. The first side of the heat reaction member is fixed to the first fixing portion  510  and the second side of the heat reaction member is fixed to the second fixing portion  520 . 
     Each of the first and second fixing portions  510  and  520  includes a hole  530 , and the soft actuator  10  may be connected to additional members using the hole  530 . 
     The body  410  and  420  may include various kinds of materials, and may be contracted or relaxed according as the heat reaction member  100  is contracted or relaxed. For example, the body  410  and  420  may include a flexible material such as a fabric. 
     Referring to  FIG. 1  again, a stitch  430  may be formed in the body, to insulate the plurality of the heat reaction members with each other. Thus, the heat reaction members are prevented from being contacted. 
     When the electricity is supplied, a first surface of the cooling part  200  is cooled, and a second surface of the cooling part  200  is heated. 
     Here, the cooling part  200  includes a cooling surface and a heating surface, and the cooling surface is cooled and the heating surface is heated when a power is supplied to the cooling part  200 . 
     For example, the cooling part  200  may include a thermoelectric element or Peltier element, or may include a flexible thermoelectric element. 
     Referring to  FIG. 2  and  FIG. 3 , the cooling surface  210  of the cooling part  200  is disposed at a side of the heat reaction member, and the heating surface  220  of the cooling part  200  is disposed at an opposite side of the cooling surface  210 . In addition, the cooling surface  210  may be disposed to make contact with at least a portion of the heat reaction member. Thus, when the power is supplied to the cooling part  200 , the heat reaction member may be cooled by the cooling surface  210 . 
     The cooling part  200  may perform Peltier effect. Due to the Peltier effect, a heat flow flows together with the current flowing in a metal, the heat seems to be generated or absorbed in a contact surface since the flow is different at each of metals making contact with each other. In the Peltier effect, the generation or the absorption of the heat is reversible, so that the heat is generated at one side and the heat is absorbed at other side due to the flow of the current and the heat is absorbed at one side and the heat is generated at other side when the flow is reversed. 
     The cooling part  200  may include a flexible material, so that the cooling part  200  may be easily connected to the fabric. 
     Referring to  FIG. 2  and  FIG. 3  again, the cooling part  200  and the body  410  and  420  are connected with each other. Thus, at least a portion of the body may be replaced by the cooling part  200 . 
     In  FIG. 2 , a portion of the surface of the body is replaced by the cooling part  200 . Here, a first end and a second end of the cooling part  200  are respectively connected to a first body  410  and a second body  420 . Here, the cooling part  200  may not be formed at an opposite surface  430  of the body. 
     Alternatively, in  FIG. 3 , a portion of the surface of the body is replace by a first cooling part  220 , and a portion of the opposite surface of the body is replaced by a second cooling part  220   a . Here, first and second ends of the first cooling part  220  are respectively connected to the first and second bodies  410  and  420 , and first and second ends of the second cooling part  220   a  are respectively connected to third and fourth bodies  410   a  and  420   a . Thus, the first and second cooling parts  220  and  220   a  face each other, with disposing the heat reaction member between the first and second cooling parts  220  and  220   a.    
     The soft actuator  10  according to the present example embodiment may further include a power supply part  310 , a sensing part  320  and a power source  390 . 
     The controller  300  controls the power supply to the heat reaction member  100 , so that the heat reaction member  100  may be changed from a contraction state to a relaxation state or from the relaxation state to the contraction state. Hereinafter, the power means the electricity. 
     For example, the controller  300  controls the power supply part  310 , to supply the power to the heat reaction member  100 . When the controller  300  transmits a power supply signal to the power supply part  310 , the power supply part  310  supplies a current to the heat reaction member  100 . In addition, when the controller  300  transmits a power stop signal to the power supply part  310 , the power supply part  310  stops supplying the current to the heat reaction member  100 . 
     Accordingly, as the current is supplied to the heat reaction member  100 , the heat is generated so that the heat reaction member  100  is contracted. As the current is stopped, the temperature is decreased so that the heat reaction member  100  is relaxed. Here, a relaxation velocity is relatively slower, and thus in the present example embodiment, the cooling part  200  is used to increase responsiveness of a relaxation operation. 
     The power supply part  310  is configured to be connected to the heat reaction member and thus the current is supplied to the heat reaction member, and further detailed explanation for the configuration is omitted. 
     The sensing part  320  includes a sensor configured to measure a bio-information or an operation of a wearer. Here, the bio-information may include electromyography. For example, the sensing part  320  may include an electromyography sensor, and thus the sensor may measure a movement or an operation (for example, a contraction operation or a relaxation operation) of a muscle of the wearer according to a gripping, a moving and a supporting of a load. Alternatively, the sensing part  320  may include a voice sensor, and thus the senor may obtain information of behavior, state and needs of the wearer according to voice information of the wearer. 
     In addition, the sensing part  430  may include a sensor configured to measure a strain of the heat reaction member  100 . For example, the sensing part  430  may include a strain gage. 
     The power source  330  supplies the electricity to at least one of the controller  300 , the power supply part  310  and the sensing part  320 . 
     The controller  300  controls the operation of the power supply part  310 , based on the information measured by the sensing part  320 . 
     For example, when the operation, like an arm bending motion, requiring the contraction of the heat reaction member is performed, the sensing part  320  provides the measured electromyography information to the controller  300 . Then, the controller  300  decides the intention of the wearer, based on the received electromyography information. In addition, the controller  300  calculates a force for bending the arm, and then obtains the final force outputted by the soft actuator  300 . Then, the controller  300  controls the power supply part  310  to generate the current supplied to the heat reaction member, so that the heat reaction member performs the operation. 
     The controller controls the power supply part  310  such that the power supplied to the heat reaction member is stopped and the power is supplied to the cooling part, when the heat reaction member is changed to be the relaxation state. Accordingly, the power supplied to the heat reaction member is stopped and the temperature starts to be decreased, and then the heat reaction member starts to be relaxed. In addition, the power is supplied to the cooling part, and the cooling surface close to the heat reaction member is operated, and as decrease of the temperature of the heat reaction member is accelerated, the relaxation speed of the heat reaction member is increased. 
       FIG. 4A  is a plan view illustrating an example contraction operation of the soft actuator of  FIG. 1 , and  FIG. 4B  is a plan view illustrating an example relaxation operation of the soft actuator of  FIG. 1 .  FIG. 5A  is a plan view illustrating another example contraction operation of the soft actuator of  FIG. 1 , and  FIG. 5B  is a plan view illustrating another example relaxation operation of the soft actuator of  FIG. 1 . 
     Referring to  FIG. 4A  and  FIG. 4B , in the present example embodiment, the cooling part is connected to the body, so as for the cooling part to be disposed at an inside of the heat reaction member along a longitudinal direction of the heat reaction member. For example, the cooling part is disposed between the first body and the second body. 
       FIG. 4A  shows the contracted state, and  FIG. 4B  shows the relaxed state. When the current flows to the heat reaction member and the heat reaction member is contracted, the body (fabric) may be contracted according to the contraction of the heat reaction member. Thus, a length of the first body is decreased from L 1 ′ to L 1 , and a length of the second body is decreased from L 3 ′ to L 3 . 
     Alternatively, referring to  FIG. 5A  and  FIG. 5B , in the present example embodiment, the cooling part is connected to the body, so as for the cooling part to be disposed at an outside of the heat reaction member along a longitudinal direction of the heat reaction member. For example, the body  400  may be disposed between the first and second cooling parts  200   c  and  200   d.    
       FIG. 5A  shows the contracted state, and  FIG. 5B  shows the relaxed state. When the current flows to the heat reaction member and the heat reaction member is contracted, the body (fabric) may be contracted according to the contraction of the heat reaction member. Thus, a length of the body is decreased from L 2 ′ to L 2 . 
     In  FIG. 4A ,  FIG. 4B ,  FIG. 5A  and  FIG. 5B , the cooling part is shown as not to be contracted or relaxed, but the cooling part may be contracted and relaxed together with the body as the cooling part includes the flexible material. 
       FIG. 6  is a structural view illustrating a soft actuator according to another example embodiment of the present invention.  FIG. 7A  and  FIG. 7B  are structural views illustrating another examples of the soft actuator of  FIG. 6 . 
     The soft actuator  11  according to the present example embodiment is substantially same as the soft actuator  10  according to the previous example embodiment in  FIG. 1 ,  FIG. 2  and  FIG. 3 , except for a cooling part  600 , and thus same reference numerals are used for the same elements and any repetitive explanation will be omitted. 
     Referring to  FIG. 6 , in the soft actuator  11  according to the present example embodiment, the cooling part  600  is configured to cool the heat reaction member down forcibly. 
     In the present example embodiment, the cooling part  600  sprays a cooling air to make direct contact with the heat reaction member  100 , to increase the relaxation speed of the heat reaction member  100 , when the heat reaction member  100  is in the relaxation state. Thus, the problem in the conventional soft actuator, in which the relaxation speed is relatively slower due to a natural cooling, may be solved. 
     To spray the cooling air inside of the body  400 , the cooling part  600  includes an inlet flow  610  configured to flow the cooling air inside of the body  400 , and a discharge flow  620  configured to flow the cooling air outside of the body  400 . Each of the inlet flow  610  and the discharge flow  620  may include a flexible material. 
     The cooling air may flow due to an operation of a fan or a blower and so on. 
     Each of the inlet flow  610  and the discharge flow  620  includes an inlet portion  611  and a discharge portion  621  which are formed as an opening. 
     As illustrated in  FIG. 6 , the inlet flow  610  is formed at a first end of the body which is an upper side of the cloth, and the discharge flow  620  is formed at a second end of the body which is a lower side of the cloth, so that the opening at the inlet portion  611  and the opening at the discharge portion  621  are opposite to each other and face each other. Thus, the cooling air may flow smoothly. 
     For example, the inlet portion  611  of the inlet flow  610  is formed along the direction substantially the same as the direction of the heat reaction member arranged inside of the body. Thus, the cooling air flows between the plurality of heat reaction members, and then the cooling efficiency may be increased. 
       FIG. 7A  shows an example of the inlet flow  610  of the cooling air, and  FIG. 7B  shows the soft actuator having the inlet flow  610  of  FIG. 7A . 
     As illustrated in  FIG. 7A , the inlet flow  610  of the cooling air includes a micro inlet flow  610   a  extending from the inlet flow  610  toward the heat reaction member longitudinally, along an up-down direction in the figure. 
     As the heat reaction member is arranged in a plural, the micro inlet flow  610   a  is arranged in a plural too, and as illustrated in  FIG. 7B , each of the micro inlet flows  610   a  is disposed between the heat reaction members adjacent to each other. Thus, the cooling effect for each heat reaction member is increased, and the heat reaction members adjacent to each other are prevented from being electrically connected. A length of the micro inlet flow  610   a  is shorter than that of the heat reaction member in the relaxation state as illustrated in  FIG. 8B . 
     As illustrated in  FIG. 7A , for each micro inlet flow  610   a , a plurality of inlet portions  611  is formed in a flow, and the opening of each of the inlet portions  611  is formed substantially perpendicular to the direction along which the heat reaction member is arranged. Thus, the heat reaction member may be cooled down more rapidly. 
       FIGS. 8A, 8B, 8C and 8D  are plan views illustrating contraction and relaxation operations of the soft actuator of  FIG. 6 .  FIG. 9A ,  FIG. 9B ,  FIG. 9C  and  FIG. 9D  are plan views illustrating contraction and relaxation operations of the soft actuators of  FIG. 7A  and  FIG. 7B . 
       FIG. 8A  and  FIG. 9A  show an initial relaxed state of the soft actuator  11 , and the power is OFF and the inlet of the cooling air is also OFF in the soft actuator  11 . 
     Then,  FIG. 8B  and  FIG. 9B  show a change from the relaxation state to the contraction state of the soft actuator  11 , and the power is ON and the inlet of the cooling air is OFF in the soft actuator  11 . Here, as the heat reaction member is contracted due to the flow of the current, the body having the fabric material is also contracted. 
     Then,  FIG. 8C  and  FIG. 9C  show a change from the contraction state to the relaxation state of the soft actuator  11 , and the power is OFF and the inlet of the cooling air is On in the soft actuator  11 . 
     Finally,  FIG. 8D  and  FIG. 9D  show a returned relaxed state of the soft actuator  11  rapidly, due to the cooling air of the cooling part  600 . Here, the cooling speed of the heat reaction member  100  is increased due to the cooling air. 
     Hereinafter, referring to  FIG. 10 ,  FIG. 11A  and  FIG. 11B , a wearable robot having the soft actuator of  FIG. 1  is explained in detail. 
       FIG. 10  is a structural view illustrating a wearable robot having the soft actuator of  FIG. 1 .  FIG. 11A  and  FIG. 11B  are example operating views illustrating an operation of the wearable robot of  FIG. 10 . 
     Referring to  FIG. 10 ,  FIG. 11A  and  FIG. 11B , the wearable robot includes a cloth body  20  and the soft actuator connected to the cloth body  20 . 
     Here, the soft actuator may be the soft actuator  10  explained referring to  FIG. 1  and may be the soft actuator  11  explained referring to  FIG. 6 . Thus, any repetitive explanation for the soft actuators  10  and  11  will be omitted. 
     The soft actuator  10  and  11 , as explained above, may be manufactured as a cloth type, and the soft actuator  10  and  11  may be easily connected to the cloth body  20 . 
     The cloth body  20  forms a base of a strength-enhancing clothing, and in the present example embodiment, the cloth body  20  forms a top clothing, but not limited thereto. 
     The cloth body  20  includes an inner skin and an outer skin, and the soft actuator  10  and  11  are disposed between the inner and outer skins. The actuator  10  and  11  is disposed close to a joint of the wearer in the cloth body  20 . 
     The cloth body  20  includes a first body fixing part  510  and a second body fixing part  520 . The first body fixing part  510  is disposed opposite to the second body fixing part  520  with respect to the position corresponding to the joint in the cloth body  20 . For example, when the joint is an elbow, the first body fixing part  510  is disposed at a brachium, and the second body fixing part  520  is disposed at a forearm. 
     Here, a first side of the soft actuator  10  and  11  may be fixed at the first body fixing part  510 , and a second side of the soft actuator  10  and  11  may be fixed at the second body fixing part  520 . 
     Each of the first and second body fixing parts  510  and  520  include a band, and the band covers an arm of the wearer to attach an artificial muscle to the arm of the wearer tightly, or to fix the first and second body fixing parts  510  and  520  to the body of the wearer tightly. 
     Referring to  FIG. 10 , the wearable robot includes a sensor  320   a  or  320   b  configured to measure a movement of the wearer. The controller  300  of the wearable robot controls the power supply part  310  to block the power supply to the heat reaction member and to supply the power to the cooling part, when the sensor measures the movement of the wearer. 
     Referring to  FIG. 11A  and  FIG. 11B , the wearable robot includes first and second soft actuators  10   a  and  10   b . Here, each of the first and second soft actuators  10   a  and  10   b  may be one of the soft actuators  10  and  11  explained above. 
     When the wearer wears the wearable robot, the first and second soft actuators  10   a  and  10   b  face each other, and the first and second soft actuators  10   a  and  10   b  are respectively disposed at inner and outer sides of an arm (or a leg). 
     Here, the controller of the wearable robot may contract the first soft actuator  10   a  and and/or may relax the second soft actuator  10   b , when the predetermined movement of the wearer is measured, for example a bending movement of the arm or the leg. The controller controls the power supply part to supply the power to the heat reaction member of the first soft actuator  10   a , and/or controls the power not to supply the power to the heat reaction member of the second soft actuator  10   b  and to supply the power to the cooling part of the second soft actuator  10   b  at the same time. 
     Hereinafter, referring to  FIG. 12  to  FIG. 14B , a massage device having the soft actuator mentioned above is explained in detail. 
       FIG. 12  is a structural view illustrating a massage device having the soft actuator of  FIG. 1 .  FIG. 13A ,  FIG. 13B ,  FIG. 14A  and  FIG. 14B  are example operating views illustrating an operation of the massage device of  FIG. 12 . 
     The massage device  30  includes at least one elastic band  610  and  620 , and the soft actuator connected to the elastic band. 
     Here, the soft actuator may be the soft actuator  10  explained referring to  FIG. 1  and may be the soft actuator  11  explained referring to  FIG. 6 . Thus, any repetitive explanation for the soft actuators  10  and  11  will be omitted. 
     Referring to  FIG. 12 , first and second elastic bands  610  and  620  are respectively connected to first and second sides of the body of the soft actuator. The controller and/or the power source  700  are connected to a first side of the first elastic band  610 . In addition, a power connector  720  is formed at a first side of the second elastic band  620 , and the power connector  720  is configured to be connected to a connector  710  formed at the power source  700 . Thus, the power source  700  may provide the power to the heat reaction member  100 . 
       FIG. 13A  and  FIG. 13B  respectively show the relaxation state and the contraction state of the massage device. In addition,  FIG. 14A  and  FIG. 14B  respectively show the relaxation state and the contraction state of the massage device with the connector connected. The massage device is contracted when used, and is relaxed when not used. 
     The controller controls the power supply part to block the power to be supplied to the heat reaction member for relaxing the massage device and to supply the power to the cooling part, when information on a user&#39;s un-usage input is received. 
     In addition, the controller controls the power supply part to supply the power to the heat reaction member for contracting the massage device and to block the power to be supplied to the cooling part, when information on a user&#39;s usage input is received. 
       FIG. 13A ,  FIG. 13B ,  FIG. 14A  and  FIG. 14B  show the cooling part  200  combined with a surface of the body receiving the heat reaction member. Here, a cooling fluid is received in the body, and a protrusion is formed on a surface on which the cooling part  200  is not combined. When the massage device is contracted, a pressure inside of the body is increased to protrude the protrusion outwardly, and thus massage effect may be increased. 
     Although not shown in the figure, the massage device may be changed variously, and as mentioned above, the body of the massage device may be partially replaced by the cooling part. 
     Hereinafter, a method for controlling the soft actuators  10  and  11  is explained in detail. 
     The method includes a relaxation step (step S 1110 ), a maximum relaxation step (step S 1120 ), and a contraction step (step S 1130 ). 
     In the relaxation step (step S 1110 ), when the heat reaction member is changed to be the relaxation state, the power supplied to the heat reaction member is blocked and the power is supplied to the cooling part. 
     For example, when the power is blocked to be supplied to the heat reaction member, the temperature of the heat reaction member is decreased and is relaxed. In addition, since the power is supplied to the cooling part, the cooling surface close to the heat reaction member is operated. Thus, as the decrease of the temperature of the heat reaction member is accelerated, the relaxation speed of the heat reaction member is increased. 
     In the maximum relaxation step (step S 1120 ), when the heat reaction member is in the maximum relaxation state, the power supply part is controlled such that the power supplied to the cooling part is blocked. 
     In the contraction step (step S 1130 ), when the information related to the contraction of the heat reaction member is received, the controller controls the power supply part to supply the power to the heat reaction member. Thus, the temperature of the heat reaction member is increased, and the heat reaction member is changed to be the contraction state. 
     The device explained above may be implemented as a hardware component, a software component, and/or a combination of the hardware and software components. For example, the device and the components explained above may be implemented by at least one conventional computer or specialized computer, such as a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any device performing an instruction and responding the instruction. 
     According to the example embodiments, a fabric type soft actuator having a cooler, in which a shape memory alloy spring is used and the cooler controls a temperature of the shape memory alloy spring, a wearable robot having the soft actuator, and a massage device having the soft actuator are provided. 
     Here, the shape memory alloy spring has a relatively large power density of a shape memory alloy wire, and also generates a relatively larger displacement (for example, about several hundred %), so that the soft actuator may be manufactured as a small, light and noiseless wearable fabric type soft actuator. 
     Although the exemplary embodiments of the present invention have been described, it is understood that the present invention should not be limited to these exemplary embodiments but various changes and modifications can be made by one ordinary skilled in the art within the spirit and scope of the present invention as hereinafter claimed.