Product Code: ICAL05_M406

Femtosecond Bulk Laser Micromachining of Microfluid Channels in PMMA
Authors:
Dave Farson, Ohio State University; Columbus OH USA
Chun Lu, Ohio State University; Columbus OH USA
Hae Choi, Ohio State University; Columbus OH USA
Presented at ICALEO 2005

Bulk machining of transparent materials is an interesting capability of offered by short pulse lasers. When a laser beam with high peak pulse power is focused inside of a transparent material, the material becomes vaporized and ionized by the laser energy and its expansion causes a small pore to form at the interaction site. By translating the beam so that multiple pores are connected, microfluidic passages can be machined inside of the material. This capability was first demonstrated in glass but, because polymers are more useful for many microfluidic device applications, creation of microfluidic channels in polymer by laser bulk machining is being studied. In this presentation, a femtosecond pulsed laser process for the creation of microfluid channels inside of PMMA is described and the affects of process parameters such as pulse energy and translation speed on channel size and quality are studied. At low pulse energies, the channel was easily closed after the focus had passed by, but at higher pulses energies, a continuous channel could be formed. For the currently optimized process, single pores with submicron diameter and visually smooth channels with no cracking and a minimum diameter of 2??m were possible.