Metal architectured plate with a natural material feel
A metal plate that has been micro-engineered to replicate the warm and elastic feel of natural materials.
Materials scientists are experienced in engineering materials to achieve the balance of properties required for a particular technical application, whether that be weight; mechanical properties such as strength, flexibility or toughness; chemical properties like corrosion resistance; or physical properties like electrical conductivity.
However, one characteristic that is not considered as often is the subjective tactile quality, or ‘feel’ of a material. This can be important for applications in architecture and design.
For instance, metals are popular design choices for both interior and exterior architecture, casings for electronics like smartphones and laptops, and household items like bowls, lamps and chairs.
Metal components are strong, robust, easy to clean and have a sleek visual appearance. However, metals can also be cold and hard to the touch, compared to the warm feel of natural materials like cork, rubber, wood, or leather.
Seeking a solution to this problem, US patent US12441078B2, granted to the Korea Institute of Industrial Technology, describes a metal plate that the inventors claim replicates the sense of tactile warmth and elasticity associated with natural materials.
The plate is formed by stacking together ‘multiple-sheet metal architectured materials’.
These materials are thin foils of metal, such as aluminium, copper, steel, stainless steel, or Invar. They have been shaped to include a plurality of base microchannels at regular intervals and another plurality of microchannels protrude between the base ones, essentially creating a corrugated structure. The foils themselves have a micro-thickness, typically between 3μm and 100μm.
The microchannels are shaped and the multiple sheets are stacked together so that channels are formed within the metal plate.
By controlling the shape and arrangement of these channels, the inventors have found they can engineer the plate’s thermal conductivity and elastic modulus, both of which affect its tactile feel. The architectured plate claimed in the patent has a thermal conductivity across its entire thickness of 0.05-10W/m·K.
The patent distinguishes the architectured plate from laminates on the basis that a metal laminate is simply formed by stacking thin metal sheets, whereas the term ‘architectured’ requires stacked truss structures that are formed from frames or structures in triangular net shapes using straight members.
The inventors describe different ways in which the architectured metal foils can be shaped and stacked to produce plates with desired combinations of tactile warmth and elasticity, while maintaining the ductility and strength associated with metal components.
In one embodiment, it appears the desirable feel can still be achieved even if the stack is covered by an outer metal sheet material without any of the microchannels. In some examples, the microchannels are not just simple protrusions, but instead have a more complex “stepped” shape formed by secondary microchannels of smaller width.
According to the patent, the individual metal sheets can be manufactured by electroforming or pressing metal foil into a suitably shaped mould. The plate can then be produced by hot pressing multiple stacked sheets together, with spacers used during pressing to achieve the desired plate thickness and ensure that channels with the necessary shapes and dimensions are formed. Alternatively, sheets can be soldered together to form the plate.
The patent includes experimental data from tests using different sheet shapes, microchannel spacings and plate thicknesses. From this data, the inventors have found that the thermal conductivity varies linearly with the plate thickness for all shapes.
They also parametrised an equation for expressing the thermal conductivity as a function of the ratio of the widths of the different types of sheet microchannels, which can be used in designing plates with desired characteristics.
The data also shows the metal plates can be engineered to replicate the thermal conductivity of different natural materials, including wood, cotton, leather, rubber, glass and rock.
The experimental results reveal that the elastic modulus can be reduced to about 1/500,000th of that of the solid metal. The inventors therefore believe both the tactile warmth and the elasticity of metal components can be controlled to desirable levels by varying the plate width and stacked layer structures.
Read the patent at bit.ly/metalarchitectured
