Laser-induced forward transfer is a direct-write process suitable for high precision 3D printing of several materials. However, the driving forces related to the ejection mechanism of the donor ma-terial are still under debate. So far, most of the experimental studies of nanosecond LIFT, are based on post process analysis of either the donor layer and/or the deposits, which were transferred to the receiving substrate. To gain further insights into the ejection dynamics, this article presents results of a series of imaging experiments of the release process of nanosecond LIFT of a 200 nm thick gold donor layer. Images were obtained using a setup which consists of two dual-shutter cameras. Both cameras were combined with a 50× long-distance microscope and used to capture coaxial and side-view images of the ejection process. Bright field illumination of the scene was accomplished by a 6 ns dual-cavity laser source. For laser fluence just above the transfer threshold, the formation of a jet and the subsequent release of a single droplet was observed. The droplet diameter was esti-mated to be about 2 μm. Analysis of the coaxial images indicates the emission of a spectral broad range light which was identified as thermal radiation.
|Title of host publication||Proceedings of LPM 2014|
|Subtitle of host publication||the 15th International Symposium on Laser Precision Microfabrication|
|Place of Publication||Vilnius, Lithuania|
|Publication status||Published - 17 Jun 2014|
|Event||15th International Symposium on Laser Precision Microfabrication, LPM 2014 - Vilnius, Lithuania|
Duration: 17 Jun 2014 → 20 Jun 2014
Conference number: 15
|Conference||15th International Symposium on Laser Precision Microfabrication, LPM 2014|
|Period||17/06/14 → 20/06/14|
Pohl, R., Visser, C. W., Römer, G. R. B. E., Sun, C., Huis in 't Veld, B., & Lohse, D. (2014). Imaging of the ejection process of nanosecond laser-induced forward transfer of gold. In Proceedings of LPM 2014: the 15th International Symposium on Laser Precision Microfabrication (pp. 129-134). Vilnius, Lithuania.