GR1010248B - Dipolar composite materials used as mechanical actuators and functional structural components - Google Patents

Abstract

The invention describes a novel composite (Dipolar Composite Material) that integrates dipolar loading in an inseparable way. DCM is a modular microstructure in the form of layers, with large Poisson ratio difference (at least 1.5). The composite provides locations of application of dipolar mechanical action, externally or internally between modules, leading to local or global curving of the layered system as a whole or at least of the fore-mentioned two fully connected layers. The dipolar loading is considered inseparable from the composite configuration and is imposed directly as surface loading and/or as body-type of loading due to inertial, thermal, electro-magnetic or chemical fields. Applications include various functional structural configurations and actuators, from macro to micro and down to nano scales. A vast range of materials can be utilized as components, with manufacturing methods like 3-D printing.

Description

Bipolar Composites as Mechanical Actuators and as Functional Structural Elements

The invention refers to the development of a new group of materials: Dipolar Composite Materials (Dipolar Compostite Materials or DCM) and their applications as mechanical actuators and as structural elements with excellent functions. DCM materials could fall under the category of "metamaterials", which are materials whose response is controlled not only by mechanical properties but mainly by the geometry, scale and orientation of the smallest structural assemblies present in their body. These materials exhibit remarkable deformation capabilities and can be used in special cases of actuators and structural functional elements. DCM materials are composed of elements (also called modules here) that exhibit marked differences in the mechanical property called "Poisson's ratio", a property related to the appearance of deformation perpendicular to the direction of the applied self-balancing coaxial mechanical load (or dipole loading). . The elements themselves consist of structured materials made of polymers, ceramics or metals. The variation of Poisson's ratio in DCM materials favors the appearance of dipole stresses that act in an unusual way, in contrast to the conventional stresses seen in classical composites. These bipolar stresses lead to deformable devices that can be very helpful in mechanical actuators as well as special structural elements.

An important class of DCM materials is that of cellular materials and in some cases that of "incremental" materials, which exhibit both positive and negative Poisson's ratio and therefore exhibit very large variations of this ratio within the same composite. ["Incremental" materials are materials which have a negative Poisson's ratio, so they contract in the direction perpendicular to the direction in which they are compressed, see Lakes (1987)]. A look at previous related research focuses on one of the earliest actuators that can be related to the present invention, which is Timoshenko's (1925) dimorphic thermostat. In this work, a composite beam consisting of two connected metal strips with different coefficients of thermal expansion was studied, which with a temperature variation could manifest a different deformation in each strip. As a result, the beam is forced to bend and this was a control device for cases of extreme temperature changes. Since then, many strip composites have been developed, consisting not only of metallic materials, which under electrical, magnetic and chemical actions exhibited actuator properties. Incremental cellular materials, sometimes referred to as hourglass (reversed honeycomb) cells, have been studied in the past and have a variety of applications such as guardrails, thermal insulators, walls, composite sandwich beams, etc. The combination of conventional honeycomb cells (positive Poisson's ratio) and hourglass cells (inverted honeycomb with negative Poisson's ratio) is very important and must be considered carefully in relation to the present case. Hou (2013) and Broccolo (2017) considered alternating layers of conventional and hourglass cell materials bonded together to form a panel, which was subjected to compression and aimed to yield an overall zero Poisson's ratio for the composite. Lin (2002, 2007) identified a continuous change of Poisson's ratio in cellular laminate (positive and negative Poisson's ratio) and investigated the overall biaxial behavior under flexural and axial loading.

Broccolo, S., Laurenzi, S. and Scarpa, F., 2017. AUXHEX - A Kirigami inspired zero Poisson's Ratio cellular structure. Composite Structures 176, 433-441.

Hou, Y., Neville, R., Scarpa, F, Remillat, C., Gua, B. and Ruzzene, M., 2013. Graded conventional-auxetic Kirigami sandwich structures: Flatwise compression and edgewise loading. Composites Part B: Engineering 59, 33-42.

Lakes, R. S., 1987. Negative Poisson's ratio materials. Science, 238,551.

Lim, T.C., 2007. On simultaneous positive and negative Poisson's ratio laminates. Basic Solid State Physics 244, 910-918.

Lim, T.C., 2002. Functionally graded beam for achieving Poisson-curving. Journal of Materials Science Letters 21, 1899-1901.

Timoshenko S., 1925. Analysis of bi-metal thermostats. Journal of the Optical Society of America 11, 233-255.

What has not been considered in previous work is the possible curvature (bending) of a multilayer composite under the action of bipolar loading (self-balanced load acting along the same line of loading). The proposed DCM hardware is different at this point, as it can incorporate this curvature and lead to new and very useful functionalities. Further control of Poisson's ratio and other mechanical properties can be achieved through the selection of appropriate cell size, crystallographic orientation, etc. Furthermore, through the capabilities of 3D printing DCM materials can be easily manufactured, at low cost and at all scales (from macro-composites to micro-composites), while other physico-chemical processes can produce DCM materials up to at nano-scales (for example by chemical deposition, by diffusion reactions, etc.). Dipolar loading can be imposed directly on the loading surface through mechanical couplings, but it can also appear as universal loading due to inertial, thermal, electromagnetic or chemical fields in which these materials are located. DCM materials can be designed to operate stably in very aggressive environments as there is no need for electrical or thermal transducers, which is required in piezoelectric and thermal bimorphs. Finally, DCM materials can be engineered to exhibit additional piezoelectric, piezoelectric, and flexoelectric response and to have tailored mass anisotropy and inhomogeneity. The efficiency of devices made of DCM materials (ratio of the work stored in the material and the work of functionality) can be very large (of the order of 0.75) while typical electro-mechanical actuators based on piezoelectricity have a maximum efficiency of around 0.40. Another advantage of DCM actuators is their simplicity of loading (simple pressure) and response which in many cases takes the form of curved geometry (bending). In summary, the proposed system converts self-balancing (bipolar) loads into bending deformation, which leads to revealing useful properties for actuators and structural elements as will be presented below. The invention uses layers of materials with large differences in the value of Poisson's ratio with bipolar loading in an inextricably linked manner that has not been considered before. Hence the name Dipolar Composite Materials (DCM).

In order to analyze and understand DCM materials we will use the following attached sketches to explain the nature of dipole charging, the possible deformations of an isolated DCM material element (module), the possible assemblies of different DCM material elements (modules) as well as the basic general arrangements in which these materials can be used as actuators and as structural elements. The overall response of a single DCM material element will be shown analytically for the case of simple structures and numerically for the case of complex geometries (eg curved surfaces, discontinuities, etc.) and/or dipole charges. Finally, we will present the prototype of a real flat beam made of DCM material, fabricated through 3-D printing with the aid of a semi-rigid polymer material, which is subjected to different dipole loadings to exhibit the bending effect we have described. The causes of bipolar charging will not be presented, as they involve interaction with other tangential elements or with external fields as presented in the previous paragraph. Electrical and electronic systems that can be adapted to DCM actuators will also not be shown, since they belong to different classes of inventions. Production methods of DCM materials include coating, extrusion, casting, chemical/physical deposition and 3D printing (preferred) technologies. However, these techniques will not be discussed further. Figures 1-7 show some examples of the DCM material as a single element (13, 14, 15, 16, 17, 18, 40) with layers including at least one (1) augmentative and one (2) non-incremental/conventional layer. Alternatively, as will be shown in the following examples, the two layers should ideally have an absolute difference of Poisson's ratio value of at least 1.50 and therefore the distinction of an accretive and a non-accretive material is irrelevant. The figure shows two-dimensional arrangements, but it is easy to generalize their consideration to three dimensions (for example in the case of platelets). The number of layers is at least two and the ratio of their length to width should be at least 4/1 (eg a minimum dimension within each layer of material should be no less than four times the thickness of layer). Bipolar loading is imposed as concentrated compressive forces (3) and/or as tensile forces (4). Other forms of dipole forces can appear as tangential forces with a concentric (6, 7, 8) or decentering (9) direction. Finally, bipolar loading can be applied in the form of two equal but oppositely acting moments (5). In all cases, the dipole charges or moments are equal and opposite in direction, yet act in the same direction. A DCM element (module) (18) does not need to be straight and its constituent layers are not required to be of equal and constant thickness or homogeneous and isotropic. In addition, dipole charges can be distributed (10, 11) and can arise from reactions of kinetic constraints imposed on them. For example, the element shown in (40) can induce bipolar charging as a combination of two different charge distributions (41, 42, 43, 44) but with the same total charge in the same charging direction and opposite direction (see the result in next arrangement (23) in Fig. 9). Bipolar loads can be applied to the ends (38), Fig. 24, of the DCM material elements, as will be seen in a later example (Fig. 24) and can be achieved with various types of clamps (37, 38), Fig. 24, or any other bipolar form of forced movement or restraint.

Figures 8-16 illustrate various assemblies of DCM material elements that create a larger DCM composite. For example, assembly (19) shows a "series-type" DCM composite, while assembly (20) shows a "parallel-type". The main feature of a DCM composition of elements is that these elements are connected to each other by elements/links (12) that concentrate the interaction of the modules in four specific points. The material of the links (12) can be similar to that of the DCM units, but it can also be of another material to ensure their strength. The connecting elements (12) can basically transfer forces, but they should be flexible enough not to transfer large moments (joint-type kinematic constraints) and are basic members of DCM element assemblies. A more general assembly of type (21) can be considered with different types and orientations of DCM elements as well as with different "point" links (12). The largest size of (12) should not exceed 1⁄4 the size of the smallest connected DCM element. In the case of a two-dimensional (planar) DCM assembly (eg (19) and (20)) the number of links (12) as described above must be exactly four, two on each side of the multilayer element, with the layers being are obligatorily formed between the two bond pairs. In this direction the flat DCM element with the 4 links is treated as a linear quadrilateral element (45) to fully cover the two-dimensional space, otherwise curved elements (46) can be used. In the case of a three-dimensional DCM assembly, the links (12) should be exactly six, three on each side of the multilayer element, not on the same line, but with the layers necessarily formed between the triads of the connection points. In this direction the 3D DCM element with the 6 links is treated as a linear hexahedral element (47) to fully cover the 3D space, otherwise curved elements (48) can be used. DCM elements in the form of pentahedra (73), heptahedrons (74), tiles or any other similar polyhedral shape can also be used. The distance between the connection points depends on the application for which the component is intended.

Figures 17-20 illustrate some structural arrangements in which DCM materials are applicable. A curved beam (22) can be made from one or several different types of DCM, applied to all or parts thereof. The layers of DCM materials must be formed along the axis of the beam. Layout (23) shows a possible application of the DCM elements on a plate and layout (24) a possible application on a shell. In these cases, the layers follow the plane of the plate or the midplane of the shell. One or more types of DCM materials can cover parts of the plate or shell. What is critical in the above structural elements is that their parts made of DCM materials should be charged with bipolar charges, while other kinds of charges can act at the same time.

Layout (25) describes a possible coating of DCM materials on an existing substrate. In this case, the non-DCM materials need not be in full contact with the substrate (26). However, all DCM coatings should be fully adhered to the substrate (27). The reason is that the necessary dipolar charge required in DCM materials is provided by the local reactions of the substrate on the DCM material, thus creating dipolarity.

The invention described below presents the simplest DCM element, which is a composite material consisting of two layers subjected to a distributed dipole load resulting in bending of the composite material. Three detailed examples follow, based on analytical calculations and numerical solutions. These fundamental examples can be used to understand the central idea of the potential of DCM materials as actuators. The last example shows the prototype from a DCM material, which is based on a cellular microstructure and which we made with 3D printing technology, proving the concept and showing how easily, quickly (within a few hours) and almost inexpensively it can be a DCM material is made.

Example 1 : Solution of an elastic element made of DCM material under uniform bipolar loading.

The simplest DCM material element considered is a two-layer beam (28), Fig. 21, with a dipole loading in the form of uniform compression (or tension) on its top and bottom faces (Fig. 4<a>). It is a plane stress problem, where the deformation elements εxy, εyz, εζX take zero values, while to avoid influences of other phenomena we consider the problem linear. The constitutive (stress-strain) equations of an isotropic material for each layer are:

εrr, = 1/Ei[σxx, -v σvv,i] [1]

εyy,i= 1/Ei[σyy,i-ν, ] [2]

Where i=1,2 indicates the layer number (as described above), Ei is the modulus of elasticity, ε is the strain and σ is the stress. The boundary conditions of this problem are: σxy= σyz= σzx= Ο, while it is true that σyy- 0 and σΧΧ^ 0. The equilibrium conditions in terms of forces and moments are expressed as follows:

The distortion in its general form is expressed as follows:

Where, k is the curvature of the beam (k= 1/ρ; ρ is the radius of curvature) and ε0 is the uniform constant axial strain along the axis of the beam.

Combining the above relations, the following expressions for curvature k and axial strain ε0 are obtained:

Equations [6] and [7] can be considered as basic for the design of DCM materials. The classical elasticity of a continuous medium limits the range of values of Poisson's ratio between -1 < ν < 0.5. Isotropic cellular honeycomb materials exhibit an equivalent Poisson's ratio of 1, while corresponding anisotropic ones can reach values of 2 or even greater. In augmentative materials (e.g. cellular hourglass-shaped, chiral-shaped materials, etc.) the equivalent Poisson's ratio can reach values up to -2. An important observation for the design of elements made of DCM materials is the fact that the curvature of the beam depends on the difference in Poisson's ratio between the two layers of material and this difference is maximized when the two layers have opposite shear.

Optimizing the response of a DCM element requires maximizing the curvature “k” for serviceability purposes and minimizing the axial strain “εo” for strength purposes (to minimize beam axial stresses). To maximize curvature the following relations must hold simultaneously:

To set the axial strain (εo) to zero, the following relation should hold in addition:

Combining the above, it turns out that the equivalent Poisson's ratio of two elastic isotropic material layers of a beam must be equal in value but opposite in sign (ν1= -ν2 with the negative value of the Poisson's ratio corresponding to a layer with incremental material), the equivalent modulus of elasticity must have the same value (E1*= E2*= E*) and the heights of the two layers should be equal (h1= h2= h). The optimal curvature of the beam, k, is calculated as follows:

Therefore, another key advantage of DCM elements is that axial deformations can be absolutely limited, thus increasing their strength. The preferred two-layer DCM cell has the aforementioned properties. The distorted image of the DCM element is shown in Figure 21b with the help of an auxiliary line canvas.

For the optimal response, as presented in the previous paragraphs (E1= Ε2= Ε , h1= h2= h and V1= -v2), the ratio of horizontal and vertical positive stresses, σxx/σyy, can be calculated to estimate the remaining stresses in a DCM composite. These residual stresses also control the strength of the element. The following applies to the height of each layer of material:

where y=T, 2 corresponds to the layer number associated with numbers (1) and (2) in all schemes (incremental and non-incremental). It turns out that in this case the maximum horizontal normal stresses appear in the region of the interface of the layers of the bimodal element (29), Fig. 21 and 22. The possible local

lamination at interface (29), Fig. 21 and 22, creates a

new energy damping mechanism where the DCM element corresponds

almost reversibly, creating applications for seismic

dampers and vibration dampers.

Example 2: The efficiency of DCMs as activators.

DCM material as a unique element when used as

actuator converts bipolar mechanical energy into mechanical energy

bending energy. Therefore, its efficiency is expected to

is high. To give some qualitative results, we will

consider Example 1 (28), Figure 21a and determine

efficiency as the ratio of the project stored in one

DCM element (beam), under uniform dipole pressure on the upper and

lower cheek, so that it acquires a certain curvature and

of the work required for the same beam to take the same

curvature under pure bending.

In a simply supported bimodal beam of length L, with properties that

correspond to the optimal solution as presented in Example

1 (Ei*= E2*= E*, h1= h2= h and v*= v1*= -v2*) the total work that

stored under uniform compression or tension is expressed by the

following relationship:

Wayy= 1⁄2Layyu [13]

where L is the length of the beam and u is the shortening in the direction

y (u=2hεyy). The resulting curvature of the dimorphic beam with the

aforementioned properties is given by the relation: k = ~εyy. The total

work considering the beam under pure bending is given by the following

expression:

wMzz= 1⁄2L Mzzk [14]

where Ma= E i k is the imposed bending moment, I=2h<3>/3

(considering unit width of the DCM element) is the torque

inertia of the beam cross-section and “k” is the target

curvature. The reason for the works is given by:

This ratio is an estimate of the efficiency of the cellular dimorphic material. For a value of Poisson's ratio ν — ±1, corresponding to isotropy for many cellular layers, the above efficiency ratio is equal to 0.75 (75%), which is an impressive performance for the DCM element.

Example 3 : Additional analytical results of a DCM element under uniform bipolar loading.

Figure 22 shows through a numerical example the use of cellular materials (30) in a DCM element (30). Two honeycomb layers are used for simplicity: one (32), Fig.22, regular honeycomb (positive Poisson's ratio) and one (31), Fig.22, hourglass (negative Poisson's ratio, augmenting materials). A bipolar uniformly distributed compressive load (33), Fig.22a, is applied to the top and bottom faces of the composite. Under the action of this load the composite material curves, as shown in Figure 22b.

To clarify the influence of dipole loading, we solve a simple DCM element (30), Fig.23a, with two layers of equal thickness and modulus of elasticity, but with a different value of Poisson's ratio: 0.5 for the non-incremental layer (2) and -1.0 for the incremental layer (1). The composite is loaded with a bipolar "pinch" compression load (35), as shown in Figure 23a (a line canvas is added to the materials to visualize the deformation details). As a result, the composite responds with a non-uniform flexural behavior, as shown in Figure 23b.

Summarizing, from examples 1 and 3 it follows that the strong curvature of DCM materials (although not always optimal) can also be achieved if their layers ensure a large absolute difference in the Poisson's ratio values, specifically a minimum value of 1.5.

Example 4: A simple DCM component template.

Figure 24 shows a simple (two-layer) template (36), Fig. 24, made using 3-D printing. It is noted that the arrangement resembles the corresponding one (130) of Fig. 22a. A bipolar charge (37), Fig. 24a, similar to that illustrated in Fig.

23a is shown in Fig. 24a where the "pinch" (bipolar) load is applied to the middle of the DCM by means of a clamp (37) which adjusts to various levels of clamping and therefore introduces different bipolar loads. Fig. 24b shows the DCM composite loaded through a clamp at the edge of its length (38), Fig. 24b, giving a very useful flexural response which is shown to be proportional to the dipole load (linear response). Upon discharge both DCM materials arrangements returned to their original straight arrangement (reversibility), thus satisfying an important property required for the ability to use DCM materials as actuators. Excessively large loads can lead to composite failure through delamination or cracking, and then the element could be useful as a mechanical energy absorber or damage controller.

The overall dimensions of this particular model are: length 23 cm, height 5 cm, width 1 cm and cell thickness 1.5 mm. However, all dimensions can be enlarged (in the order of meters) or reduced (in the order of millimeters) maintaining the curvature effect. The material of the cells was Z-PLA acrylic polymer (modulus of elasticity 1.83 GPa and Poisson's ratio 0.3) and apparently this is not a limitation since other materials such as metals, elastomers etc. they can be used depending on the requirements arising from the use (e.g. strength, high temperatures, elasticity, etc.). The cellular geometry consisted of two layers with the same thickness and the same equivalent modulus of elasticity of 0.029GPa. However, the Poisson's ratio of the growth layer (hourglass cells) (1) was -1.0 and that of the nongrowth layer (2) was 1.0.

Applications

Below, we present some preferred applications that can be viewed and designed as both 2D or axonometric as well as 3D. These designs are illustrated in Figures 25-37. The geometries of Figs. 25-37 can be considered as side views in the case of planar (2D) arrangements with the out-of-plane dimension being small relative to the in-plane dimensions or large relative to the in-plane dimensions and in this case last case the dipole charge is assumed to extend as a linear charge in the out-of-plane direction. Axisymmetric dimensions can easily be represented by planar figures, assuming that the view given is a side view and the axisymmetric line is on the plane of the figure. Finally, 3D versions of the illustrated planar shapes are easy to design and will not be discussed further. The response of the proposed provisions is almost self-evident if the preceding examples have been understood. We will focus on layouts with one or two simple DCM materials, however obvious extensions of these can be made with more DCM elements (19), (20), (21) and/or with variable elements (18), (48), (47) ), (46), (45), (73), (74), (14), (13), (12), (11), (15), (16).

A microvalve arrangement (49), Fig. 26, uses a recirculating applied bipolar load (59), Fig. 26, across two interconnected DCM elements creating a recirculating reverse bend and when immersed in fluid, acts as a microvalve. Other DCM elements can be connected in series (19), Fig. 8, and can create a fluid micro-stirring device.

A micropump (50), Fig. 50, is created when an oscillating dipole charge (60), Fig. 50, is applied to a simple DCM element creating an antisymmetric bend useful in pushing the fluid to create a differential pressure across the fluid volume . The device can be extended by connecting other DCM elements in series, creating micromechanisms that make "creeping" movements and may be useful in cleaning microtubules and human or animal arteries. "Skinning" a substrate with a layer of DCM material (61), Fig. 32, creates applications in braking (51), Fig. 32, so that the surface under the action of tangential dipole action (8), Fig. 32, protrudes out of plane, as a result of which it creates obstacles for bodies that slide or roll on this surface. Note that the action is a first-order phenomenon since the dipole charge is tensile. Such an action can be produced (52), Fig. 33, by the combination of a dipole charge acting perpendicular to a surface (61), Fig. 33. DCM coating can be realized on very small scales by suitable use of two layers of paint form , but it can also be applied on the scales of civil engineering projects with the help of large-scale cellular materials (31, 32), Fig. 36, in the form of DCM layers (53), Fig. 36. Another application is the creation of barrier conditions of the relative movement between surfaces, by adjusting the maximum value of the applied vertical load (63), creating specific peaks and valleys for micro- and nano-instrument platforms up to and including special road surface applications for military, naval and aircraft purposes as well as foundations of buildings. The aforementioned results cannot be seen without the DCM layer of materials. Further understanding of the planar surface effect is made with the next application (external bending comes from surface reactions). Such devices, when there is movement within a fluid, can be used to adjust the aerodynamics or hydrodynamics of the body in which they are placed.

Simpler braking devices can be designed as shown in (58), Fig. 27 where tangential dipole loads (6, 7, 8), Fig. 27, also lead to bending of the element which interferes with other mechanical parts and locks their movement (58), Fig. 27.

The zero-bending fit (54), Fig. 28, is evident when the DCM elements are properly clamped at one end and the bending moment (65), Fig. 28, is applied at the other end. As explained in Example 24b, applying clamps to the DCM elements creates bipolar loading and as a result a global bending. The end result of the combination of said clamping and bending moment can be designed to yield zero ultimate bending strain in the beam. This can be an interesting feature for special purpose structures and can be extended to plates and shells. In a similar setting, checking the deformation of a structural element (55), Fig.

29, made of DCM materials can be achieved with collars (66) to hold the beam in a straight arrangement under external loads (65), Fig. 29, see Fig. 24a for a basic understanding of superposition of flexural behavior . Collars and clamps impose the required bipolar loading.

An extension of the zero bending effect can be made to selected statically certain beam, slab and shell systems. An example is the frame (57), Fig. 34, consisting of two DCM beams connected by a rigid joint (68), Fig. 34 at least 5 times stiffer than the material of the DCM elements. The same rigid connectors (68), Fig. 34, must also be connected to the end of the frame elements. Intermediate collars (66), Fig. 34, may also be used for optimum response. As in previous applications (54, 55), Fig.

28 and 29, the maximum external load (69), Fig. 34, can be found to keep the frame "locked" in its original position. The frame (57), Fig. 34, is statically fixed and in the case where DCM elements are not used the frame would have sufficient capacity for relative movement of the rolling support and for rotation of the hinged support (75), Fig. 34. Other possible applications of DCM material is to allow interface plasticization (29), which makes DCM materials adequate as seismic excitation dampers and vibration dampers useful in many frames, building foundations, roads, or other civil engineering structures. Plate systems, as in Example (77), Fig. 35, can be realized by connecting plates (or even shells) with rigid connectors (68), Fig. 35 and clamps (78), Fig. 34, on a substrate (eg foundation) or other structures.

Micro-accelerometers (56), Figs. 30 and 31, can use DCM elements with dipole charges induced through a mass placed (67) on a body and accelerated through an external field (e.g. earthquake, gravity , body movement).

Innovative capabilities can be designed with DCM materials, as well as nanoarrays as precision devices (70), Fig. 30 and 31, e.g. micro and nano penetrants and etchers, micro beam charging devices for atomic microscopes. The clamp (64), Fig. 37, is adjusted and controlled to keep the DCM element straight and as a result the entire beam of DCM elements becomes excessively stiff. Thus the reaction at the other end of the beam (71), Fig. 37, due to the deformation of the element (72), Fig.

37, can be adjusted with great precision.

Claims (10)

1. An innovative composite material (DCM: Dipolar Composite Material) is proposed with a simple (13, 14, 15, 16, 17, 18, 40, 45, 46, 47, 48, 73, 74) or linked microstructure in modules ( 19, 20, 21) in the form of layers, with each module having at least two fully connected layers (1, 2), preferably one of them consisting of growth material with a high value of negative Poisson's ratio and the other consisting of a non-augmenting material with a high value of positive Poisson's ratio and generally at least two layers that have a difference in the absolute values of the Poisson's ratio preferably above 1.5. Layers are not required to be flat or of constant thickness in all directions. The composite provides points of application of bipolar mechanical action (3, 4, 5, 6, 7, 8, 9, 10, 11, 41, 42, 43, 37, 38, 60, 65), directly or indirectly by means of links of a specific type (12), with bipolar mechanical loading leading to local or global curvature of the multilayer system as a whole or at least of the two fully connected layers. Dipole loading is considered an integral part of the composite and is applied directly as surface loading and/or as field loading due to inertial, thermal, electromagnetic or chemical fields. 2. As in Claim 1, with the DCM materials forming structural elements in the form of a straight or curved beam (22), flat plate (23), or shell (24). Workability relates to desired deformation and/or development of initial stresses that can improve overall strength. 3. As in Claim 1, the DCM materials are applied as surface paints or surface coatings to surfaces of other substrate materials (25). 4. As in Claim 1, wherein the layers (1, 2) can be cellular materials (31, 32), a molecular layer, a fabric, a perforated layer, a foam material, a polymer, a ceramic material, an elastomer. Materials can be tuned to behave elastically to achieve reversibility, or to behave plastically or viscoplastically at the interlayer interface (29) so that DCMs play the role of energy absorbers in mechanical dampers. 5. As in Claims 2 or 3, with the structural element to be used as an actuation system (49, 50, 54, 56, 65, 70), preferably pressure valves, micro-cleaning devices, switches, microscope surfaces, micro-accelerometers, dynamometers, strain gauges and micropumps. 6. As in Claim 3, wherein the DCM materials can be used as anti-etch and anti-penetration protective layers (51, 52, 53). 7. As in Claims 2 or 3, wherein the DCM layers can be used in a braking system from macro to micro scale (58). 8. As in Claim 2, with the static certain structural elements being able to form structural systems (57, 77) of frames, panels, baffles, planes and foundations which exhibit no or very little flexural movement. 9. As in Claim 3, wherein the DCM layer can be used to control aerodynamic and hydrodynamic behavior of the curved surface. 10. As in Claim 3, wherein the DCM layer can be used to support human or animal movement as an artificial skin actuator, a vascular bandage and an orthopedic splint.