FirstBuild is helping make a molded plastic diffuser for the Trilife cellular computing project.
The MATLAB file (rainbow colored inset) got CNC milled into a Modulan tool for vacuum forming thanks to Jeremy Turner and Randy Reeves at First Build.
We are looking at PETG for the plastic that will be formed over this mold, because PETG is paintable and can also be laser cut. These diffusers will create the triangular light reflectors that we currently get from folding paper. The paper works great, except it crumples up a lot in transit.
Testing the electromagnetic field signature for a hair dryer
We continue working with the Welch group at U of L on tracking appliance usage in homes and offices. The goal is for individuals to track their own energy consumption with mobile sensors. Here’s Dr. Welch’s Ph.D. student Anand Kulkarni running an appliance near a copper plane antenna to pick up its electromagnetic field (EMF) signature. Five appliances were classified using a decision tree algorithm. For more, see IEEE Sensors Journal:
There are a lot of low-cost pressure sensors out there but many are made for surface mount, like the one at the left, which is fairly huge for a surface mount part. You are expected to solder the gold leads of this pressure sensor to a printed circuit board (PCB) or adapter. What about when you are still designing your system and have not made a PCB yet? Check out Jaz’s quick way of making the MPXV7007DP fit in a prototyping breadboard using headers that most electronics labs have handy.
Surface charge density on a metal half spool, by Jordan Meyer in Coventorware
Some students have finished things, and others have started new projects.
Jordan Meyer finished her independent study, generating a beautiful image of surface charge density on metal structures using CoventorWare (pictured above), which will plug into Jaz Beharic’s research on flow through metallized membranes. Also last semester, Sherman Dowell and Martin Dombi completed independent studies that provided examples for future students in the ECE412 microcontroller course.
We welcome two new independent study students, Tayce Lassiter and Caleb Sheehan. Tayce is working on impedance sensing in paper and fiber microfluidics, and Caleb, fine-tuning our nanoparticle patterning process. They join Thomas Johnson, who is finishing up his work on mapping and measuring thermal effects of gold nanoparticle coatings.
In our never-ending obsession with spraying metal on 3D structures to create interesting circuits without lithography, we found DualLock, an engineered “hook and loop” fastener. DualLock is a forest of tiny molded plastic mushrooms. When you shove two pieces of DualLock together, the mushroom caps interlock. It takes some force to separate them, and the strength depends on the kind of DualLock you bought. The tiny “low-profile” DualLock mushrooms are the weakest, but still pretty strong, and the cap diameters are <1mm, putting them in the “micro” realm.
In the gaudy purple and green electron microscope image, evaporated metal coats the tops of the mushrooms and floor, but not the stems. So you get one circuit on the floor, and a second circuit that can be formed by bending the DualLock so the caps touch. The insulating stems look wavy, because they become charged in the electron microscope. With no place for the charge to go, it builds up and then the electron beam deflects.
