Fig. 4: Letterpress style kapok flower patterning.
From: Programmable photoacoustic patterning of microparticles in air
a The letterpress style target image. b The final results of the letterpress style flower patterning. c Three sequential frames of the outer area pattern. We blurred certain lines to highlight the evolving trajectory of the innermost lines of the first frame. d The process of removing particles from the outer area of the flower. e Three sequential frames of the inner area pattern. f The progress of driving particles in the inner area of the flower.
