Time-resolved imaging of flyer dynamics for femtosecond laser-induced backward transfer of solid polymer thin films

Feinaeugle, M. (author), Gregorčič, Peter (author), Heath, D. J. (author), Mills, B. (author), Eason, Robert (author)

We have studied the transfer regimes and dynamics of polymer flyers from laser-induced backward transfer (LIBT) via time-resolved shadowgraphy. Imaging of the flyer ejection phase of LIBT of 3.8 [micro]m and 6.4 [micro]m thick SU-8 polymer films on germanium and silicon carrier substrates was performed over a time delay range of 1.4- 16.4 [micro]s after arrival of the laser pulse. The experiments were carried out with 150 fs, 800 nm pulses spatially shaped using a digital micromirror device, and laser fluences of up to 3.5 J/cm2 while images were recorded via a CCD camera and a spark discharge lamp. Velocities of flyers found in the range of 6-20 m/s, and the intact and fragmented ejection regimes, were a function of donor thickness, carrier and laser fluence. The crater profile of the donor after transfer and the resulting flyer profile indicated different flyer ejection modes for Si carriers and high fluences. The results contribute to better understanding of the LIBT process, and help to determine experimental parameters for successful LIBT of intact deposits.

• Language: English
• Keywords: laser-induced backward transfer, time-resolved shadowgraphy, femtosecond laser-induced micro-processing, polymer thin films, additive manufacturing, SU-8
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2017
• Number of pages: Str. 1231-1238
• Numbering: Vol. 396
• PID: 20.500.12556/RUL-98578
• UDC: 535(045)
• ISSN on article: 0169-4332
• COBISS.SI-ID: 15103003
• Publication date in RUL: 28.02.2018

Record is a part of a journal

• Title: Applied surface science
• Shortened title: Appl. surf. sci.
• Publisher: Elsevier
• ISSN: 0169-4332
• COBISS.SI-ID: 3283215

Secondary language

• Language: Slovenian
• Keywords: lasersko povzročen prenos snovi, senčna fotografija, femtosekundni laserji, mikroprocesiranje