Nanoparticles are boring SQUARE HOLES in our silicon wafers! The gold nanoplates from the O’Toole group enhance the etch rate in our usual silicon-etching process. Mysterious square pores appear when nanoparticles are present on the silicon. Others have made conical nanopores in a different etch chemistry and with different gold nanoparticles, and used them as …
Author Archives: cindy.harnett@louisville.edu
Inflatable actuator with two stable states
Here is the latest iteration of the macro bistable actuator. We inflated two air pockets to make this 3-D printed plastic beam contort into an S-shape; this shape is an important step on the way to “snap-through” of our small and large bistable beams. The work continues Fidel Tewolde’s earlier project and makes good use …
Continue reading “Inflatable actuator with two stable states”
Bistable inclined beam in slow motion
Here is a spring steel beam snapping from one stable shape to another in our bending tester as it goes past the critical angle. The beam is about 5 cm long and vibrates at 240 Hz. Thanks to Roger Bradshaw and Bill Hnat for the slow-motion video.
Selective heating with two types of nanoparticles
Our paper “Wavelength specific excitation of gold nanoparticle thin films” came out and is available online. Working with gold nanoplates from our collaborators in the O’Toole group, we are looking at thermal expansion in thin films as a way to bend microscale beams. These nanoparticles can be highly wavelength selective. We found that we could …
Continue reading “Selective heating with two types of nanoparticles”
Bending some beams
We are looking at thin-film beams embedded in flexible surfaces. Not only can these beams act as micro-switches, but they can quickly jump to a new shape if the curvature of the surface changes. Their “snap-through” behavior is controlled by the amount of compression put into the beam at fabrication time. The concept works for …