Time-resolved study of absorbing film assisted laser induced forward transfer of Trichoderma longibrachiatum conidia

We have characterized the absorbing film assisted transfer of Trichoderma longibrachiatum conidia using a synchronized laser for illumination. The transfer laser used was a KrF excimer laser (lambda = 248 nm, FWHM = 30 ns) and the ejected material was illuminated parallel to the quartz plate by a nitrogen laser pumped Coumarine 153 dye laser beam (, = 453 nm, FWHM = I ns) electronically delayed relative to the transfer UV pulse. Our time-resolved investigations determined that the ejection velocity front of the conidia plume from the donor surface during the transfer procedure was 1150 ms (-1) at 355 mJ cm(-2) applied laser fluence. On the basis of the measured data, the acceleration of the emitted conidia at the plume front was approximately 10(9) x g. The conidia survived the absorbing film assisted forward transfer and associated mechanical shear without significant damages suggesting that the technique might be applicable to other more fragile types of biological objects and applications.