To make the molds, an ultraviolet laser was used to drill holes through sheets of polyethylene terephthalate
Tapered holes were made to produce conical needles; straight-walled holes were also made to produce cylindrical tubes
Mylar was chosen as the mold material for its ease of removal after microneedle formation and its relatively inexpensive cost
The laser was operated at 200 Hz with a 248-nm wavelength and a typical energy density of 2.0