Micro-injection Molding of Biodegradable Polylactic Acid Microstructures Using Amine-containing Gas-permeable Hybrid Molds

Polylactic acid (PLA), a biodegradable material derived from renewable sources, has been challenging to fabricate through injection molding, owing to its narrow crystallization range and poor heat resistance. Conventional injection molding also encounters difficulties with gas venting in the cavity, which impedes microscale processing. This study successfully performed micro-injection molding of standard PLA under typical conditions. Using an amine-containing gas-permeable hybrid molds, PLA microstructures measuring 1.2 μm in height and 2.7 μm in base diameter were successfully molded, demonstrating high moldability. This study established the viability of micro-injection molding for PLA and may provide an important foundation for the future development of micro-surface fabricated devices made of PLA in the biomedical field, such as blood coagulation prevention medical devices based on microfabrication technology.