Full text loading...
(Color) Schematic of the fabrication process. A microscope objective (NA 0.8) focuses laser pulses from an 11‐MHz ultrafast Ti:sapphire laser system inside a doped polymer sample. The microscope objective also provides in‐situ imaging. A high‐precision and long‐travel three‐axis translation stage scans the sample in the x‐, y‐ and z‐directions while an acousto‐optic modulator shutters laser pulses to control exposure. The result is a direct‐written dielectric‐embedded silver structure in 3D.
(Color online) 3D rendering of stacks of sequential in‐situ bright‐field optical microscopy images of fabricated structures. For clarity, the z‐scale is stretched by a factor of 1.6 relative to the x‐ and y‐scales. (a,b) An array of silver dots fabricated in a tent structure at an exposure of 1.3 × 106 pulses with 0.15 nJ per voxel. Neighboring rows of dots are in different z‐planes. The stage was translated at 10 μm/s during fabrication. (c) Portion of an array of tent structures fabricated using the same parameters.
(Color online) High‐resolution SEM images of a patterned sample. (a) An image of a 2D array of dots and (b) its corresponding EDS silver elemental map confirm that silver structures are grown in areas irradiated by the laser. Close‐up views of individual dots shown (c) head on and (d) at a 61° tilt angle. SEM imaging requires a washing step to avoid sample contamination from additional silver growth driven by the electron beam.
TEM image of fabricated silver structures. The silver does not grow as a single crystal in each irradiated voxel. Instead, the silver structures are composed of agglomerations of smaller silver nanoparticles. The inset shows a close‐up view of a silver nanoparticle.
Article metrics loading...