Harnett Lab

Our collaborative work on thermal processing of gold nanoplates with the O’Toole group (U of L Bioengineering) is accepted (update: published) at Materials Letters. We’ve used their triangular gold nanoplates to induce local heating of microelectromechanical (MEMS) structures with infrared lasers. The nanoplates are typically the first layer to go onto the MEMS wafer. In this paper, we show that temperatures in the 200-300 C range can shift the absorbance wavelength of the nanoplates by rounding the corners, far lower than the melting temperature of bulk gold (>1000 C). Thanks to careful mapping, Jaz and Kurtis were able to find the same tiny nanoplates (70 nm side lengths) before and after heating, in both electron and optical microscopes. Temperatures reach the 200-300 C range during MEMS processing unless you take care to use low-temperature materials and methods. So, when using gold nanoplates, either keep your cool or prepare for them to behave differently in the final device — absorbing shorter wavelengths than they started with.

Our paper “Absolute length sensor based on time of flight in stretchable optical fibers,” by Ji-Tzuoh Lin and C. K. Harnett, is accepted at IEEE Sensors Letters . What’s new over our previous work? We measured the travel time of a laser pulse, rather than its amplitude in a stretchable optical fiber. This method is less sensitive than amplitude measurements are to manufacturing variations and surface curvature, making it good at measuring lengths over surfaces with varying shapes. Check it out here https://paperpile.com/shared/K8BdV6

If you’re building robots in the US you probably order from this catalog. It is time to place an order and I have only one small item in the cart. Can anyone in the lab think of anything they need? (Not sponsored content. Is that even possible?)

5733T83. Traffic light. We need to control traffic flow in the hallway for social distancing. Let’s get one for each end of the building. Think of how many Capstone projects will be launched.

2701T36. The front load cargo tricycle is needed for so many reasons, like 1) Look at it.
No, we are not going to get one. Let’s just enjoy the idea that it exists and can hypothetically get here Wednesday.

Sensors for Wearables and Robotics PhD Research Assistantship

Updated Summer 2020

Immediate & future opportunity for a Ph.D. student in Electrical and Computer Engineering at the University of Louisville in the area of sensors for wearable devices and robotics. Go to our Join the Lab page for more details! Fill out our interest form, get on our radar.

Remote work got standardized when Chris N. suggested we work with “bricks.” Plastic bricks emerged from boxes and tubs in different cities. He designed some 3D printed parts with pockets for bricks, so he could click them into place on this torque-vs-angle testing platform when the parts arrived from campus. No need to ship the heavy platform, because he also had some of those slab-like bases around.

Even now, with students near enough to campus to pick up and drop off items, the bricks are paying off because every photo has a scale bar. Good idea, Chris, one to keep handy for future collaborations at all levels!