National Cheng-Kung University

Chung-Yu Yu

Chen-Kuei Chung

Yun Chen

Chin-An Ku

Tsung-Han Chen

An invisible ink and a method of making the same are revealed. The invisible ink includes anodic aluminum oxide (AAO) powder and at least one solvent. The method of making the invisible ink includes the steps of taking an aluminum substrate and carrying out anodic oxidation on the aluminum substrate at least once to form an anodic aluminum oxide (AAO) layer on a surface of the aluminum substrate, separating the AAO layer from the aluminum substrate and pulverizing the separated AAO layer to get AAO powder, and adding the AAO powder into a solvent to obtain the invisible ink.

Invisible ink and method of making the same

A method of manufacturing colorful thermal insulation films is provided. A substrate is connected with a metal adhesion layer and then the metal adhesion layer is connected with a porous anodic aluminum oxide (AAO) layer. A porosity of the AAO layer is changed by pore-widening. Thereby the thermal insulation film produced shows the color by the structure color of the AAO layer. Thus no dyes and organic compounds are required to be added during manufacturing process and environmental pollution caused by these substances can be avoided. The pore-widening changes the porosity of the AAO layer and further provides convenient color adjustment so that the colorful thermal insulation film with different colors can be produced easily. Besides providing attractive appearance, the colorful thermal insulation film filters out light with specific wavelengths.

Method of manufacturing colorful thermal insulation film

The present invention discloses a using method of a rewritable board. It comprises applying or removing a fluid on the rewritable board for writing repeatedly, wherein the rewritable board is an aluminum based material sequentially having a porous aluminum oxide layer and a metal layer thereon, and wherein the porous aluminum oxide layer has a porosity ranging from 10% to 80%.

Using method of rewritable board

A method for preparing invisible anodic aluminum oxide (AAO) patterns is revealed. The method includes a plurality of steps. First take an aluminum substrate. Then anodize the aluminum substrate for the first time to get a first anodic aluminum oxide (AAO). Next perform photolithography so that a photoresist forms a pattern on the aluminum substrate with the first AAO. Lastly anodize the aluminum substrate for the second time so that a second AAO is formed on the pattern and the pattern becomes invisible.

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Tainan, Taiwan

Chung-Yu Yu