A mechanical metamaterial comprising a chiral structure and a reentrant structure repeatedly layered to form a 3D structure with improved compressive response is disclosed. The 3D structure of the present invention is a metamaterial which can be perfectly and easily produced by a photocuring 3D printing process without any internal support. The introduction of modified carbon nanotubes into the printing composite material improves the compression resistance and impact resistance of the products and increases the service life through the special periodic structure. The application of 3D printing technology in fabricating mechanical metamaterials can break through the processing limitation of traditional processing technology or microelectronics manufacturing technology to make three-dimensional periodic structures.

In a first aspect, a metal-clad polymer film includes a polymer film adhered to a first metal layer. The root-mean-square roughness (S.sub.q) of the interface between the polymer film and the first metal layer is less than 1 m. The peel strength between the polymer film and the first metal layer is greater than 5 N/cm after 168 hours of aging at 150 C. when tested for a polymer film having a thickness in the range of from 25 to 75 m and a first metal layer having a thickness of 18 m in accordance with IPC-TM-650 test methods. The thickness of the first metal layer is 12 m or less. The polymer film includes a first thermoplastic polyimide layer. In a second aspect, an electronic device includes the metal-clad polymer film of the first aspect. In a third aspect a process includes for forming a double-sided metal-clad polymer film.

Certain embodiments described herein are directed to composite materials effective for use in deep draw processes. In some examples, the composites can be used to provide vehicle panels such as, for example, vehicle underbody panels. In some configurations, the composite comprises a fiber reinforced polymer core and a skin material disposed on at least some portion of the fiber reinforced polymer core, in which the skin material comprises a basis weight of at least 65 g/m2 and an elongation at break of at least 20%.

A kirigami metamaterial with tunable auxetic property under large tensions and a design method for it. The kirigami metamaterial is composed of a plurality of square unit cells in orderly arrangement. The unit cells are arrayed in periodic, gradient and inhomogeneous layouts, corresponding to the kirigami metamaterials with homogeneous, gradient and inhomogeneous auxetic properties. The design method is as follows: Firstly, the heuristic design of the unit cell is obtained by using the structural optimization method for fully considering out-of-plane deformations. Secondly, the optimization result obtained from the above step is processed by geometric reconstruction and parametric modeling, and then the auxetic properties with different geometric parameters are obtained. Finally, the kirigami metamaterial is composed of a plurality of unit cells arrayed into a specific layout. The present invention can achieve a variety of tunable auxetic trends adjusted with the tensions by modifying the cut parameters.

A multilayer film includes a first skin layer, a second skin layer, and a core layer. The core layer includes at least two lanes of material. Each of the lanes of material of the core layer contacts each of the first skin layer and the second skin layer.

Provided are cementitious panel that include a swellable material within a core layer, a dense layer, and/or a sheet of facing material that make up a cementitious panel, as well as methods of manufacturing such cementitious panels that include a swellable material and methods of providing a moisture or water barrier in a cementitious panel.

Device surfaces are rendered superhydrophobic and/or superoleophobic through microstructures and/or nanostructures that utilize the same base material(s) as the device itself without the need for coatings made from different materials or substances. A medical device includes a portion made from a base material having a surface adapted for contact with biological material, and wherein the surface is modified to become superhydrophobic, superoleophobic, or both, using only the base material, excluding non-material coatings. The surface may be modified using a subtractive process, an additive process, or a combination thereof. The product of the process may form part of an implantable device or a medical instrument, including a medical device or instrument associated with an intraocular procedure. The surface may be modified to include micrometer- or nanometer-sized pillars, posts, pits or cavitations; hierarchical structures having asperities; or posts/pillars with caps having dimensions greater than the diameters of the posts or pillars.

A reinforcing member includes a plate-shaped member that is made of a fiber-reinforced resin in which a continuous fiber is used as a reinforcement fiber and that has a first surface and a second surface. The plate-shaped member includes an outer circumferential portion that defines an outer edge of the plate-shaped member, a convex portion that is convex on a side of the first surface in an area inside the outer circumferential portion, and a plurality of concave portions that are concave on the side of the first surface in an area inside the convex portion.