3D Nanoprinter

Nov 14, 2014

Objective

The 3D nanoprinter (in theory) allows bottom-up construction of nanoscale devices and materials. Its primary goal is to help computational advances in material simulation, by creating nanostructures that match theoretical findings (such as metamaterials and fractal material structures) that can then be subjected to experiments to see whether they match the theoretically predicted properties. To construct the material, nanoscale 'starting blocks' are placed into a desired position, and then heated to a sintering temperature with a laser. The high surface energy of nanoparticles makes sintering a quick way to join the building block materials to each other. The nanoscale construction goal was not reached, but assembly of simple microstructures was achieved, using microspheres as starting blocks.

Photos

Overview


From left to right, two side views and a top view of the device.

From the side, the large condenser lens is visible, along with a fiber line that carries the sintering laser. The stage consists of two stepper motors for the X and Y axes, and a piezo actuator for the Z axis, along with a manual coarse mechanical adjustment. From the top, the micromanipulator used to position microspheres in place for sintering is visible.

Laser


A photo of the laser in the dark.

This long-exposure photo with the room lights off shows the laser path. The laser is a 440nm 500mW diode laser.


The laser reaches the sample through the microscope objective.

The laser is focused by the objective lens, onto a less than 1 micron spot on the sample.

Microspheres


Melted silver microspheres.

One challenge was finding the correct laser power level to sinter, rather than melt, the small particles. The SEM image above shows what a high power pulse does to the particles.

Results