Abstract: The present invention relates to a package structure for a microsystem, comprising a substrate, a chip, an adhesive structure, a carrying substrate, a micro-mechanism, a plurality of wires, an annular body and a transparent plate. The chip is placed on the substrate. The annular adhesive structure having an opening is placed on the chip. The carrying substrate is placed on the adhesive structure, thus forming an interspace between the chip, the adhesive structure and the carrying substrate. The pressure inside the interspace can be balanced with the pressure outside the interspace through the opening. The micro-mechanism is disposed on the carrying substrate. The annular body is formed on the substrate and the transparent plate is attached on the annular body, thus forming a closed chamber between the substrate, the annular body and the transparent plate. The chip, the micro-mechanism, the adhesive structure, the carrying substrate and the wires are disposed within the closed chamber.

Abstract: The present invention relates to a production method of lactic acid-based polyurethanes. In the first phase of the product ion, the monomeric lactic acid is polymerized into an oligomer, the molecular weight thereof being about 500 to 10,000. Next, the oligomer thus obtained is copolymerized with an isocyanate reacting with the free hydroxyl and carboxyl groups thereof into polyurethane with a high molecular weight. To make the oligomer react with diol prior to the copolymerization is unnecessary according to the invention. The lactic acid used need not be absolutely pure, and by modifying the process, various biodegradable end products can be obtained therefrom, which according to the invention are appropriate for the material of disposable packages, agricultural film or planting pots, or as a coating of fertilizer granules.