WO2025110942A1

WO2025110942A1 - A new flat plate pulsating heat pipe with membrane type variable channel

Info

Publication number: WO2025110942A1
Application number: PCT/TR2024/050197
Authority: WO
Inventors: Burak MARKAL; Orhan Aydin
Original assignee: Karadeniz Teknik Universitesi Teknoloji Transferi Uygulama Ve Arastirma Merkezi
Current assignee: Karadeniz Teknik Universitesi Teknoloji Transferi Uygulama Ve Arastirma Merkezi
Priority date: 2023-11-22
Filing date: 2024-03-05
Publication date: 2025-05-30
Anticipated expiration: 2026-05-22

Abstract

The subject of the invention is a new flat plate pulsating heat pipe with membrane type variable channels that prevents the temperature increase and provides temperature control during the operation of systems with a control unit or any heat-producing component, such as supercomputers, data centers, unmanned aerial vehicles and wearable technological devices; the invention is a new flat plate pulsating heat pipe with membrane type variable channels, in which movable channel walls with a membrane-type flexible structure are subject to constant deformation due to bubble movements that occur as a result of the boiling of the working fluid via the thermal energy received from the part to be temperature controlled; the invention is a new flat plate pulsating heat pipe with membrane type variable channels in which the cross-sectional area of the channels containing the working fluid changes dynamically at different levels, and the membrane-type flexible structure movable channel walls serve as a mechanism that performs the suction-pumping process, as in a pump; the invention is a new flat plate pulsating heat pipe with membrane type variable channels that enables effective cooling by improving both the pulsating/oscillatory movement of the working fluid and ensuring its high-speed circulation through the sucti-compression movements created by the membrane-type flexible moving channel walls; the invention is a new flat plate pulsating heat pipe with membrane type variable channels that reduces size-volume-weight-production cost by reducing dependence on the number of channels and offers high cooling performance independent of gravity; it is a new flat plate pulsating heat pipe with membrane type variable channels that can operate spontaneously without receiving power from any electrical source.

Description

A NEW FLAT PLATE PULSATING HEAT PIPE WITH MEMBRANE TYPE VARIABLE CHANNEL

The technical field to which the invention relates:

The invention relates to a novel flat plate pulsating heat pipe with a membrane type variable channel that prevents a possible temperature rise during operation of systems having a control unit or any heat-generating component, such as supercomputers, data centers and wearable technological devices.

In particular, the invention relates to a new type of flat-plate pulsating heat pipe having membrane-type flexible movable channel walls, the channel cross-section of which continuously changes due to bubble movements with the boiling of the fluid contained therein, the changing channel cross-section creates pressure fluctuations and moves the refrigerant, which can be used to provide temperature control in military equipment, unmanned aerial vehicles and all electronically controlled systems.

The known state of the technic:

In parallel with advances in materials and processing techniques, computer- based technological systems or devices have become an indispensable part of both daily life and areas that prioritize human safety and comfort such as defense industry, satellite and communication systems, health industry, data management, computer- based technologies basically include all devices that are composed of processors with electronic circuits or components that can process and manage data or perform defined commands within their scope. Therefore, such technological devices are exposed to the problem of temperature rise during their operational life as current flows through their electronic circuits and components. Uncontrolled temperature rise can lead to various problems, such as reduced performance, limited processing capacity, loss of functionality and even mechanical deformation of the relevant systems. In general, safe temperature limits are between 70°C and 120°C, depending on the area of use of the electronic devices. New generation cooling techniques are needed to provide effective temperature control within these limits.

One of the alternative coolers developed to control the temperature rise in control units consisting of electronic components or computer-based devices is pulsating heat pipes. In the known state of the technic, the pulsating heat pipes used or designed consist of flow passages with rigid channel walls, which are opened in a curved form formed by bending a rigid-walled capillary tube or in an interconnected curved form on a flat plate. All pulsating heat pipes in the known state of the technic have rigid channel walls, whether they are formed by opening channels of rectangular cross-section on a flat plate or by bending circular tubes. In order for the pulsating heat pipe to perform the cooling process, the fluid in it must take heat from the evaporator zone, carry it to the condenser zone and return to the evaporator zone to form a continuous cycle. In other words, in order for any pulsating heat pipe to be used as a thermal control device, the fluid in it must continuously move and/or circulate between the evaporator and condenser zones. In addition to the pressure difference between the evaporator and condenser zones, the fluid movement in the heat pipe is caused by pressure fluctuations (perturbations) caused by bubbles that form and collapse at different times and locations as a result of the boiling of the working fluid under the influence of the heat received from the component to be cooled through the evaporator zone of the heat pipe. Therefore, geometric configurations with a large number of parallel channels (> 10) are needed to create the necessary or sufficient pressure perturbation for pulsating heat pipes to work. This increases the pulsating heat pipe volume, production cost, production time and the amount of working fluid, which is undesirable. In addition, the performance level of the working heat pipes is directly proportional to the pressure turbulence levels within the channels. In this context, in order to increase the performance of pulsating heat pipes by reducing the dependence on the number of channels, there is a need for original and new types of pulsating heat pipes that will improve the pressure perturbation level and bring innovation in terms of working mechanism. In the known state of the technic, pressure turbulences or perturbations, which play a critical role in the operation of pulsating heat pipes, can only be achieved by the effect of bubble formation and collapse phenomena trapped between the rigid walls. In the state of the technic, there is no flat plate type pulsating heat pipe whose channels are separated from each other by membrane-type moving walls, where the channel cross-sections vary continuously with time and position, and the pressure perturbation required for flow is provided by moving channels that act as pumping by suction and compression movements.

The patent document numbered "US11320209B2" in the known state of the technic was examined. The subject invention relates to a pulsating heat pipe having a channel plate including a first surface, a second surface, first channels, second channels, first passages, second passages, at least one chamber and at least one third passage. The invention discloses a pulsating heat pipe in which the first channels and the chamber are formed on the first surface, the channels are formed on the second surface, the first passages, the second passages and the third passage pass through the first and second surfaces, the chamber is located opposite the third passage and has a closed end connected to at least one of the second channels via the third passage. In the system in question, there is no structure in the form of a flat plate whose channels are separated from each other by membrane-type movable walls, where the channel cross-sections vary continuously with time and position, and the pressure perturbation required for flow is provided by movable channels that act as pumping by suction and compression movements.

The utility model file "CN204329690U" in the known state of the technic discloses a heat dissipating device, in particular a pulsating heat pipe for removing heat from an electronic device. The utility model discloses a tubular pulsating heat pipe having channels of different density in the evaporator and condenser zones, wherein the evaporator area is reduced to remove heat from small electronic devices, and the tubes in the condenser section are designed to occupy more space. In the system in question, there is no structure in the form of a flat plate whose channels are separated from each other by membrane-type moving walls, where the channel cross-sections vary continuously with time and location, and the pressure perturbation required for flow is provided by moving channels that act as pumping by suction and compression movements.

The patent document numbered "CN101776408A" in the known state of the technic was examined. The invention relates to a pulsating heat pipe used in areas where high levels of heat transfer occur, such as waste heat boilers and chip cooling. In particular, the invention discloses a pulsating heat pipe which reduces the start-up temperature, increases heat transfer, is in the form of a curved ring channel and consists of an expansion chamber externally attached to the condenser region by a connecting channel. In the system in question, there is no structure in the form of a flat plate whose channels are separated from each other by membrane-type moving walls, where the channel cross-sections vary continuously with time and position, and the pressure perturbation required for the flow is provided by moving channels that act as pumping by suction-compression movements. The patent document numbered "CN105222628A" in the known state of the technic was examined. The invention relates to a pulsating heat pipe comprising a hot end base, a cold end base and a capillary tube array. In particular, the invention discloses a pulsating heat pipe with a capillary tube array in which the lower end of the capillary tube array is arranged in the hot end base, the upper end of the capillary tube array is arranged in the cold end base, a first cavity is formed in the cold end base and connected with the upper end of the capillary tube array, a second cavity is formed in the hot end base and connected with the lower end of the capillary tube array, a heat- conducting surface is arranged in the lower part of the hot end base, a liquid filling channel is provided, and the capillary tube array is positioned perpendicular to the heat transfer surface. In the system in question, there is no structure in the form of a flat plate whose channels are separated from each other by membrane-type moving walls, where the channel cross-sections vary continuously with time and position, and the pressure perturbation required for flow is provided by moving channels that act as pumping by suction-compression movements.

The patent document numbered "US2015060019A1" in the known state of the technic was examined. The invention relates to a heat pipe for heat dissipation and, in particular, to a multi-tube pulsating heat pipe provided with at least one chamber connector having a cross-sectional area larger than the total cross-sectional area of the multiple heat pipes, or with at least one pair of penetration holes. The system in question does not have a structure in the form of a flat plate whose channels are separated from each other by membrane-type movable walls, where the channel cross-sections vary continuously with time and position, and where the pressure perturbation required for flow is provided by movable channels acting as pumping by suction and compression movements.

The patent document numbered "CN103776288A" in the known state of the technic was examined. The invention relates to heat pipes with mass and heat transfer. In particular, the invention discloses pulsating heat pipes with double evaporators or condensers, formed by bending a circular tube, which can perform the function of heating or cooling two spaces. In the system in question, there is no structure in the form of a flat plate whose channels are separated from each other by membrane-type moving walls, where the channel cross-sections vary continuously with time and position, and the pressure perturbation required for flow is provided by moving channels that act as pumping by suction-compression movements. The patent document numbered "CN105547023A" in the known state of the technic was examined. The subject invention relates to a variable diameter pulsating heat pipe for cooling microelectronic and semiconductor components. In particular, the invention discloses a variable diameter pulsating heat pipe with different hydraulic diameters of adjacent main passages, an evaporator zone, a heat insulated section, a condenser zone, a vacuum opening at the left end of the condenser zone and a filling opening at the right end. In the system in question, there is no structure in the form of a flat plate whose channels are separated from each other by membrane-type moving walls, where the channel cross-sections vary continuously with time and position, and the pressure perturbation required for the flow is provided by moving channels that act as pumping by suction-compression movements.

The patent document numbered "CN101533810A" in the known state of the technic was examined. The invention relates to a foamed pulsating heat pipe radiator. In particular, the invention discloses a foamed pulsating heat pipe radiator comprising a plurality of snake-shaped closed circuits comprising an emitting foam, a pulsating heat pipe, a heat sink, a fan and a pulsating heat pipe fluid. In the system in question, there is no structure in the form of a flat plate, the channels of which are separated from each other by membrane-type moving walls, the channel cross-sections are constantly changing with time and position, and the pressure perturbation required for the flow is provided by moving channels that act as pumping by suction and compression movements.

The patent document numbered "TW201116793A" in the known state of the technic was examined. The invention subject to the application relates to a pulsating/oscillating heat pipe. The invention discloses a pulsating heat pipe comprising a channel system including a plurality of first channels and a plurality of second channels, wherein the plurality of first channels are arranged in such a way as to have an alternating arrangement along the channel system with a plurality of second channels, and wherein the cross-sectional areas of the first and second channels are different from each other. In the system in question, there is no structure in the form of a flat plate whose channels are separated from each other by membrane-type movable walls, where the channel cross-sections vary continuously with time and position, and the pressure perturbation required for flow is provided by movable channels that act as pumping by suction-compression movements. The patent document numbered "WO2021133970A1", which is in the known state of the technic, has been examined. The invention subject to the application relates, in particular, to passive microchannel pulsating heat pipe devices and related methods; within the scope of the invention, a preferably closed-loop microchannel pulsating heat pipe is disclosed, preferably a closed-loop microchannel pulsating heat pipe comprising a microchannel plate having obstacles along its inner walls to increase the surface area and artificial bubbling areas for evaporation of the working fluid, in which different shapes of obstacles can be considered on one or more lower, side and upper walls of the plate to improve heat transfer. In the system in question, there is no structure in the form of a flat plate whose channels are separated from each other by membrane-type moving walls, where the channel cross-sections vary continuously with time and position, and where the pressure perturbation required for the flow is provided by moving channels acting as pumping by suction and compression movements.

As a result, in the known state of the technic, there is no pulsating heat pipe, structure, design or system in the form of a flat plate whose channels are separated from each other by membrane-type moving walls, where the channel cross-sections vary continuously with time and location, and where the pressure perturbation required for the flow is provided by moving channels that act as pumping by suctioncompression movements. Due to the deficiencies in the known state of the technic and the inadequacy of the existing solutions in the subject, it was deemed necessary to make an innovation in the relevant technical field.

Purpose of the invention:

The most important aim of the invention is to provide temperature control for military equipment, unmanned aerial vehicles, wearable technological devices and all electronically controlled systems and to prevent temperature-related deformations with a technique in which the channels are separated from each other by membrane type movable walls, the channel cross-sections vary continuously with time and position, and the pressure perturbation required for flow is provided by movable channels that act as pumping by suction-compression movements.

Another important aim of the invention is to create a new agitation mechanism by means of the structure of the channel walls that continuously changes the channel cross-section at different levels and times, in addition to the pressure turbulence that occurs during the bubble formation and collapse processes of the working fluid, and to increase the heat transfer performance by improving the flow circulation.

Another aim of the invention is to develop a new passive membrane type variable channel flat plate pulsating heat pipe with a new driving force based on phase change and fluid circulation in heat transfer, offering advantages in terms of volume, processing time and cost, with reduced dependence on the number of channels.

Systems with electronic control units are used from devices that facilitate daily life to complex systems in all critical sectors such as defense industry and satellite/space systems. In parallel with advances in materials and processing techniques, the surface area and hence the volume occupied by electronic control units or electronic components are shrinking, but the density of subcomponents such as transistors is increasing. As a result, more heat is released during operation and the amount of heat released increases with technological development. In order for electronic circuits or systems to operate as designed and in line with expectations, the safe operating temperature upper limit must not be exceeded. Although it varies depending on the area of use, this limit is generally between 70°C and 120°C. As electronic device sizes decrease and processor speeds increase, more thermal energy needs to be removed from the heat transfer surface to keep the components at the desired temperature. Therefore, cooling techniques or devices with higher heat removal capacity are needed. In addition, due to the dimensions that can be reduced to mini, micro and even nano scales in electronic systems, new generation coolers are needed in wearable technologies such as virtual reality glasses, ultra-thin televisions, mobile phones, tablet computers and many similar applications, which do not contain additional equipment such as pumps, piping lines, ultra-compact, passive in terms of operating type, but provide effective cooling. Pulsating heat pipes are among the promising cooling devices with this potential. In such structures, in addition to the pressure difference between the evaporator and condenser zones, the driving force required for the fluid to move back and forth between the evaporator and condenser zones in pulsating and oscillating form, in other words, for the system to operate and perform the cooling process, is provided by pressure perturbations within the system. Pressure perturbations occur as a result of bubble formation and collapse within the flow passages. In the known state of the technic, pulsating heat pipes contain only rigid channel walls, whether or not the channel cross-section varies along a channel pair or loop; hence, they have constant channel cross-sections over a distance. Therefore, in the absence of gravity support (horizontal or with the evaporator on top), the number of channels or loops must be above a certain value in order to generate sufficient pressure perturbation through pure bubble formation and collapse within the rigid channel walls. For existing structures this corresponds approximately to a minimum of 10 channels or 5 loops. The requirement for a minimum number of channels, which restricts the design, leads to an increase in the total heat pipe volume and thus increases the production time, increases the production cost and limits the areas of use. Furthermore, the performance of a pulsating heat pipe is strongly dependent on the intensity of the pulsating/oscillating fluid circulation. Therefore, even in pulsating heat pipe operation, pressure fluctuations provided only by bubble formation and collapse processes significantly hinder the desired performance. Therefore, there is a need for structures/techniques that provide new mechanisms to support fluid oscillation and pulsation movements and improve fluid circulation between the evaporator and condenser zones. In this context, a new flat plate pulsating heat pipe with membranetype variable channels is superior to the known state of the technic because it has a new structure, technique and working mechanism in which the channels are separated from each other by membrane-type moving walls, the channel cross-sections vary continuously with time and position, and the pressure perturbation required for flow is provided by moving channels that act as pumping by suction and compression movements. In addition, a new flat plate pulsating heat pipe with membrane type variable channels is superior to the state of the technic in terms of reducing the dependence on the number of channels, reducing the size-volume-weight-production cost, and providing high cooling performance independent of gravity, thanks to the above-mentioned features.

A new flat plate pulsating heat pipe with membrane type variable channels is superior to the state of the technic in terms of the driving force mechanism it creates and uses to provide the fluid movement required to achieve high cooling performance.

Explanation of the figures:

FIGURE -1 : Perspective view of a new flat plate pulsating heat pipe with membrane type variable channel.

FIGURE -2: Perspective view of the main body.

FIGURE -3: Disassembly view of a new flat plate pulsating heat pipe with membrane type variable channel. Reference numbers

WF. Working fluid (refrigerant)

100. A new flat plate pulsating heat pipe with membrane type variable channel

110. Main body

120. Cover

130. Filling channel plug

140. Vacuuming channel plug

150. Evaporator zone

160. Adiabatic zone

170. Condenser zone

180. Membrane type flexible movable channel wall

190. Channels

200. Filling channel

210. Vacuuming channel

Description of the invention:

The subject matter of the invention is a new flat plate pulsating heat pipe with a membrane type variable channel (100), an electronic control unit, and therefore a device with any processor (workstations, data centers, laptops, virtual reality glasses and the like), which allows the thermal energy generated during the operation of the device to be transferred from the source area to a heat receiving environment (such as environment air). Thus, the temperature of the processors can be kept under control. The subject of the invention is a new flat plate pulsating heat pipe with a membrane type variable channel (100), having a main body (110), a cover (120), a filling channel plug (130) and a vacuuming channel plug (140). The inventive new flat plate pulsating heat pipe with membrane-type variable channel (100) is divided into three zones over its total length, namely, evaporator zone (150), adiabatic zone (160) and condenser zone (170). Thus, the temperature of the processors can be kept under control. The subject of the invention is a new flat plate pulsating heat pipe with a membrane type variable channel (100), having a main body (110), a cover (120), a filling channel plug (130) and a vacuum channel plug (140). The inventive new flat plate pulsating heat pipe with membrane type variable channel (100) is divided into three zones over its total length, namely, evaporator zone (150), adiabatic zone (160) and condenser zone (1 0). The evaporator zone (150) corresponds to the part that sits on the component to be cooled or whose temperature is to be controlled. The adiabatic zone (160) corresponds to the part where there is no heat exchange with the external environment or the object to be cooled. It can also be covered with insulation material when necessary. The condenser zone (170) is the part where the thermal energy, which is taken from the component to be cooled and transported through the working fluid (refrigerant) (WF), is discharged into any heat sink or, in other words, into a heat well. Only environment air can be used as a heat well, or forced air flow provided by a fan or heat sinks through which the refrigerant passes can be used. The main body (110) is the basic element of a new flat plate pulsating heat pipe with membrane type variable channels (100) of the invention and has flexible membrane type movable channel walls (180). Between the membrane type flexible moving channel walls (180), there are channels (190) in which the fluid circulates by making pulsating and oscillating back and forth movements. The working fluid (refrigerant) (WF) is loaded into a new flat plate pulsating heat pipe of the inventive membrane type with variable channels (100) through the filling channel (200) in the main body (110). At the same time, the air in a new flat plate pulsating heat pipe with a new membrane-type variable channel (100) of the inventive membrane type is evacuated through a vacuuming channel (210) in the main body (110).

The cover (120) is joined to the main body (110). This joining can be done using any welding technique or adhesive. The bonding method does not matter if the sealing is ensured. The vacuuming channel (210) is vacuumed by means of a vacuum pump and the vacuuming channel plug is inserted. Working fluid (refrigerant) (WF) is filled from the filling channel plug (130) with a syringe or other means. Any refrigerant such as deionized water, ethanol, methanol, methanol, R134a, etc. can be used as the working fluid (refrigerant) (WF). The main factors determining the type of working fluid are chemical compatibility with the material and the desired temperature range. The ratio of the working fluid (refrigerant) (WF) volume to the total internal volume of the system can vary between 0.1 and 0.8. After filling with the working fluid (refrigerant) (WF), the filling channel plug (130) is closed and a new flat plate pulse heat pipe with a variable channel (100) of the membrane type according to the invention is ready for use.

A new flat plate pulsating heat pipe with a membrane-type variable channel (100) of the inventive membrane type is positioned so that the evaporator zone (150) corresponds to the component to be cooled or the temperature of which is to be controlled. The evaporator zone (150) is a region corresponding to a portion of the base or, in the other words, a portion of the platform area of a new flat plate pulsating heat pipe with a membrane-type variable channel (100). As a result of the thermal energy received from the component to be cooled, the working fluid (refrigerant) (WF) starts to boil in the evaporator zone (150). The vapor bubbles that are formed exhibit shape changes that change rapidly with time and position by growing, collapsing or coalescing. The membrane type flexible movable channel wall (180) in the membrane type flexible structure are subjected to continuous shape changes due to the changes occurring in the bubbles and cause the cross-sectional area of the channels (190) containing the fluid to change dynamically at different levels. Thus, the membrane-type flexible moving channel walls (180) act as a device for suction and discharge, as in a pump. Unlike a pump, this action takes place spontaneously without any electrical supply. Therefore, a new flat plate pulsating heat pipe with a membrane-type variable channel (100) of the invention is a passive cooling device that performs cooling without consuming energy from any external source. The suction-compression process created by the membrane-type flexible movable channel walls (180) improves both the pulsating/oscillatory movement of the working fluid (refrigerant) (WF) and its highspeed circulation, thereby enabling efficient cooling. Both the presence of membrane type flexible movable channel walls (180) and the new driving force and operating mechanism provided by the respective channel walls make the inventive membranetype variable channel flat plate pulse heat pipe (100) superior to the state of the technic in terms of geometry, flow physics and operating mechanism.

In a new flat plate pulse heat pipe with membrane type variable channels (100), the number of membrane type flexible movable channel walls (180) in the membrane type flexible structure can be increased or decreased. Furthermore, the number and position of the filling channel (200) and the vacuuming channel (210) may be different. The material used in the construction of a new flat plate pulse heat pipe with a membrane type variable channel (100) can be any metal material with a high heat conduction coefficient such as copper, silver, brass, gold, or a semiconductor material such as silicon. The aforementioned changes basically do not affect the working mechanism or the specific characteristic of the inventive membrane-type variable channel novel flat plate pulsating heat pipe (100).

Claims

1. A new flat plate pulsating heat pipe (100) with membrane type variable channels that prevents the temperature increase and provides temperature control during the operation of systems with a control unit or any heat-producing component, such as supercomputers, data centers, unmanned aerial vehicles and wearable technological devices; has movable channel walls (180) in a membrane-type flexible structure are subjected to continuous shape change due to bubble movements in the form of growth, collapse and coalescence that occur due to the boiling of a working fluid (IA); has cross-sectional area of the channels (190) containing the working fluid (IA) changes dynamically at different levels, and the moving channel walls (180) with a membrane-type flexible structure serve as the mechanism that performs the suction-pumping process, as in a pump; and that allows effective cooling by improving both the pulsating/oscillatory movement of the working fluid (IA) and ensuring its circulation at high speed, with the suctionpressure movements created by the membrane-type flexible movable channel walls (180); and that reduces the size-volume-weight-production cost by reducing dependence on the number of channels and offers high cooling performance independent of gravity characterized by comprising;

• A working fluid (refrigerant) (WF) that starts to boil under the influence of the thermal energy generated on the surface to be temperature controlled, undergoes bubble formation-collapse-merging processes and circulates between a evaporator zone (150) and a condenser zone (170) with the suctioncompression movements created by the membrane-type flexible moving channel walls (180), and removes the thermal energy it receives from the area where the temperature controlled component is located with the circulation it performs,

• The membrane type flexible movable channel walls (180), which are subject to continuous shape changes due to changes in bubbles, which cause the cross- sectional area of the channels (190) containing the fluid to change dynamically at different levels, which act as a device that naturally performs suctioncompression without expending any electrical energy, which enables effective cooling by improving both the pulsating / oscillatory movement of the working fluid (refrigerant) (WF) with the suction-compression process it creates and providing high speed circulation,

• The main body (110) with membrane-type flexible movable channel walls (180), with channels (190) through which the fluid circulates in pulsating and oscillating back-and-forth movements, with a filling channel (200) through which the working fluid (refrigerant) (WF) is loaded, with a vacuuming channel (210) through which vacuuming is performed,

• The cross-sectional area includes channels (190) that dynamically change at different levels during operation.

2. The novel flat plate pulsating heat pipe of the membrane type with a variable channel (100) according to claim 1 , characterized in that comprising a cover (120) in addition to a filling channel plug and a vacuum channel plug as a closed-circuit cooler.

3. The new flat plate pulsating heat pipe with a membrane type variable channel (100) according to claim 1 , characterized in that performing the cooling process by circulating the fluid by means of the pumping force generated due to the bubble movements of membrane type flexible movable channel walls (180) of the membrane type flexible structure without being powered by any electrical source.