Fabrication of hollow microneedles by optical vortex illumination

Molding technologies are mostly employed to fabricate microneedles (MNs) for medical and cosmetic applications, such as drug delivery and skin care systems. However, such technologies are ill suited for bioabsorbable materials with high viscosity, thus, there is no report concerning hollow bioabsorbable MNs, so far. We propose a novel laser processing technology, which enables us to fabricate a hollow bioabsorbable MN by simply irradiating both optical vortex for fabricating MNs and Gaussian beam for drilling holes on a hyaluronic acid sheet.