In some embodiments, the present invention is directed to an actuator which includes at least the following: a pre-stretched electro-active polymer film being pre-stretched in a single or biaxial planar directions; at least one first semi-stiff conductor attached to a first surface of the pre-stretched electro-active polymer film, wherein the first surface is parallel to the single or biaxial planar stretch directions; at least one second semi-stiff conductor attached to a second surface of the pre-stretched electro-active polymer film, wherein the second surface is opposite to the first surface; where the semi-stiff conductors are configured to: fix the pre-stretched electro-active polymer film in a pre-stretched state and allow the pre-stretched electro-active polymer film to expand; a pair of mechanical connectors coupled to each end of an active region of the pre-stretched electro-active polymer film.

The present invention relates to a multilayer film comprising: • an inner layer system comprising a first surface and a second surface; • a first skin layer bound to the inner layer system at the first surface of the inner layer system; and • a second skin layer bound to the inner layer system at the second surface of the inner layer system; wherein • the inner layer system comprises a first ethylene-based polymer; and • at least one of the first or the second skin layer(s) is a sealing layer and comprises a second ethylene-based polymer having a peak melting temperature T.sub.pm of at least 10° C. below the T.sub.pm of the first ethylene-based polymer, T.sub.pm being determined as peak melting temperature in accordance with ASTM D3418 (2008); wherein the multilayer film is a bi-directionally oriented film wherein the orientation is introduced in the solid state. Such film allows for the production of a sealed package having a sufficiently high sealing strength at reduced sealing temperatures, also referred to as the seal initiation temperature.

The invention provides a biaxially oriented polypropylene film, wherein a relationship between a loop stiffness stress (S [mN]) in a longitudinal direction and a thickness (t [μm]) satisfies the formula S≥0.00020×t.sup.3, a relationship between a loop stiffness stress (S [mN]) in a width direction and the thickness (t [μm]) satisfies the formula S≥0.0010×t.sup.3, and a heat shrinkage rate of the biaxially oriented polypropylene film at 150° C. is not higher than 10% in the longitudinal direction and not higher than 30% in the width direction, a heat shrinkage rate of the biaxially oriented polypropylene film at 120° C. is not higher than 2.0% in the longitudinal direction and not higher than 5.0% in the width direction, and the heat shrinkage rate at 120° C. in the longitudinal direction is lower than the heat shrinkage rate at 120° C. in the width direction.

The invention provides a biaxially oriented polypropylene film, wherein a relationship between a loop stiffness stress (S [mN]) in a longitudinal direction and a thickness (t [μm]) satisfies the formula S≥0.00020×t.sup.3, a relationship between a loop stiffness stress (S [mN]) in a width direction and the thickness (t [μm]) satisfies the formula S≥0.0010×t.sup.3, and a heat shrinkage rate of the biaxially oriented polypropylene film at 150° C. is not higher than 10% in the longitudinal direction and not higher than 30% in the width direction, a heat shrinkage rate of the biaxially oriented polypropylene film at 120° C. is not higher than 2.0% in the longitudinal direction and not higher than 5.0% in the width direction, and the heat shrinkage rate at 120° C. in the longitudinal direction is lower than the heat shrinkage rate at 120° C. in the width direction.

Provided is a biaxially oriented polypropylene film that has high stiffness, has excellent heat resistance at a high temperature of 150° C., easily maintains a bag shape when being made into a packaging bag, and has less pitch shift during printing or fewer wrinkles in a sealed portion when being heat-sealed. A biaxially oriented polypropylene film, wherein a half width of a peak derived from an oriented crystal in a width direction in azimuth dependence of a (110) plane of polypropylene α-type crystal obtained by wide-angle X-ray diffraction measurement is not larger than 27°, and a tan δ area in the width direction obtained from a ratio (E′E″) of a storage elastic modulus (E′) to a loss elastic modulus (E″) obtained by dynamic viscoelasticity measurement is not smaller than 0.2 and not larger than 0.4.

Provided is a biaxially oriented polypropylene film that has high stiffness, has excellent heat resistance at a high temperature of 150° C., easily maintains a bag shape when being made into a packaging bag, and has less pitch shift during printing or fewer wrinkles in a sealed portion when being heat-sealed. A biaxially oriented polypropylene film, wherein a half width of a peak derived from an oriented crystal in a width direction in azimuth dependence of a (110) plane of polypropylene α-type crystal obtained by wide-angle X-ray diffraction measurement is not larger than 27°, and a tan δ area in the width direction obtained from a ratio (E′E″) of a storage elastic modulus (E′) to a loss elastic modulus (E″) obtained by dynamic viscoelasticity measurement is not smaller than 0.2 and not larger than 0.4.

A method includes attaching a clip array to opposing edges of a polymer thin film, the clip array having a plurality of first clips slidably disposed on a first track located proximate to a first edge of the polymer thin film and a plurality of second clips slidably disposed on a second track located proximate to a second edge of the polymer thin film, applying a positive in-plane strain to the polymer thin film along a transverse direction by increasing a distance between the first and second clips, and decreasing an inter-clip spacing amongst the first clips and amongst the second clips along a machine direction while applying the in-plane strain to form an optically anisotropic polymer thin film. During stretching, a strain rate of the thin film may be decreased and/or a temperature of the thin film may be increased.

In some embodiments, the present invention is directed to an actuator which includes at least the following: a pre-stretched electro-active polymer film being pre-stretched in a single or biaxial planar directions; at least one first semi-stiff conductor attached to a first surface of the pre-stretched electro-active polymer film, wherein the first surface is parallel to the single or biaxial planar stretch directions; at least one second semi-stiff conductor attached to a second surface of the pre-stretched electro-active polymer film, wherein the second surface is opposite to the first surface; where the semi-stiff conductors are configured to: fix the pre-stretched electro-active polymer film in a pre-stretched state and allow the pre-stretched electro-active polymer film to expand; a pair of mechanical connectors coupled to each end of an active region of the pre-stretched electro-active polymer film.

A multi-axial geogrid possesses a series of interconnected strands or ribs that are arranged along at least two different axes within the plane of the structure. The strands or ribs have an aspect ratio, defined as the ratio of the thickness to width, of greater than 1.0, thickness being the direction normal to the plane of the structure. The geogrid can be manufactured by modifying the process parameters in order to create high aspect ratio ribs, using any of the various known methods for producing geogrids. A reinforced civil engineering structure, and method therefor, is formed by embedding in soil one or more horizontal layers of geogrid having high aspect ratio ribs. The reinforced structure shows improved rutting performance when subjected to vehicular traffic.

A multi-axial geogrid possesses a series of interconnected strands or ribs that are arranged along at least two different axes within the plane of the structure. The strands or ribs have an aspect ratio, defined as the ratio of the thickness to width, of greater than 1.0, thickness being the direction normal to the plane of the structure. The geogrid can be manufactured by modifying the process parameters in order to create high aspect ratio ribs, using any of the various known methods for producing geogrids. A reinforced civil engineering structure, and method therefor, is formed by embedding in soil one or more horizontal layers of geogrid having high aspect ratio ribs. The reinforced structure shows improved rutting performance when subjected to vehicular traffic.