Harnett Lab

Shaf gave a talk at the Nature Inspired Surface Engineering conference in early June. Ahead of the presentation, he needed to know how strong his MEMS* devices were so he put some micro cantilevers in a microfluidic channel. The tips of the cantilevers moved as the flow rate was increased. In this video, you can also see the parabolic shape of the flow velocity profile. Meaning, cantilevers near the center of the channel deflect more because they are in faster-flowing water than the cantilevers near the walls. Results were encouraging for the feasibility of suspending MEMS in microfluidic channels to measure temperatures and local flow rates inside micro chemical reactors.

*Microelectromechanical systems

Electrical and Computer Engineering Ph.D. students in wearable sensors and robotics sought starting Spring 2020, $22.5k stipend + full tuition. To get started, please fill out this form. If  you are interested in Ph.D. opportunities beyond spring, a summer Co-op, course credit, or postdoctoral opportunities, you are also welcome to fill out the form and select these other options.

Oliver, Kurtis and Logan presented their optical sensor in the Speed School of Engineering Design and Innovation Showcase at the end of the Spring 2019 semester. They worked with super small circuit boards for our tiny new side-looking optical sensors, creating smooth and streamlined housings for our stretchable optical fibers so they can be quickly connected to electronics for sensing, and disconnected for washing. The 3 student team also sent the wireless data to a mobile phone instead of a database as previous teams had done, and they focused on materials, repeatability, and accuracy of the stretching measurements where previous teams had focused more on wireless communication and database software. Not pictured, but a secret ingredient for success: Dylan (independent study Masters student making those circuit boards & getting them to collect data from multiple optical sensors) and Chris (work-study student who developed a motorized platform for cycling individual fibers through repeated stretching measurements).

We are making the embroidered electromagnetic actuators more portable with a new rechargeable battery-powered compact driver board, and adding soft lightweight payloads that can spin and bounce. Such soft sculpted objects might manipulate delicate natural items like tiny seeds, feathers, and fine fibers. Their low inertia gives them a surprising speed in this real-time video. Next to investigate: how to get rolling and other cyclic motions beyond spinning.

This is a tiny version of a bristlebot, threaded onto a copper wire. Instead of making it carry a self-contained motor and battery, we used the wire as an electromagnet to vibrate a small permanent magnet hanging below the device. Instead of toothbrush bristles, there is a goose down feather touching the wire. These ~1cm long devices travel toward the “bird” end of the feather when run at 100 Hz. The feather gives it a preferred direction of motion using natural “bristles” that are about 5-10 microns in diameter, the same size scale as the flexible microstructures we have been making in the cleanroom.