Background: Much of researchers' efforts to foster wider implementation of educational innovations in STEM has focused on understanding and facilitating the implementation efforts of faculty. However, student engagement in blended learning and other innovations relies heavily on students' self-directed learning behaviors, implying that students are likely key actors in the implementation process. This paper explores the ways in which engineering students at multiple institutions experience the self-directed selection and implementation of blended learning resources in the context of their own studies.
View Article and Find Full Text PDFCarbon dioxide (CO) has been linked to many deleterious health effects, and it has also been used as a proxy for building occupancy measurements. These applications have created a need for low-cost and low-power CO sensors that can be seamlessly incorporated into existing buildings. We report a resonant mass sensor coated with a solution-processable polymer blend of poly(ethylene oxide) (PEO) and poly(ethyleneimine) (PEI) for the detection of CO across multiple use conditions.
View Article and Find Full Text PDFSens Actuators B Chem
November 2018
Here we report on the development of polyimide-based flexible magnetic actuators for actively combating biofouling that occurs in many chronically implanted devices. The thin-film flexible devices are microfabricated and integrated into a single-pore silicone catheter to demonstrate a proof-of-concept for a self-clearing smart catheter. The static and dynamic mechanical responses of the thin-film magnetic microdevices were quantitatively measured and compared to theoretical values.
View Article and Find Full Text PDFThough the ultrasonic excitation of surface waves in solids is generally realized through the use of a contact transducer, remote excitation would enable standoff testing in applications such as the nondestructive evaluation of structures. With respect to the optimal incident wave profile, bounded inhomogeneous waves, which include an exponentially decaying term, have been shown to improve the surface wave excitation efficiency as compared to Gaussian and square waves. The purpose of this work is to investigate the effect of varying the incident wave spatial decay rate, as applied to both lossless fluid-solid interfaces and to solids with viscoelastic losses included.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
August 2016
Here we report on the development of novel polyimide-based flexible magnetic actuators for improving hydrocephalus shunts. The static and dynamic mechanical responses of the thin-film magnetic microdevices were quantitatively measured. The bacteria-removing capabilities of the microfabricated devices were also evaluated.
View Article and Find Full Text PDFThe transmission of airborne sound into high-impedance media is of interest in several applications. For example, sonic booms in the atmosphere may impact marine life when incident on the ocean surface, or affect the integrity of existing structures when incident on the ground. Transmission across high impedance-difference interfaces is generally limited by reflection and refraction at the surface, and by the critical angle criterion.
View Article and Find Full Text PDFWhen infants first begin to sit independently, they are highly unstable and unable to maintain upright sitting posture for more than a few seconds. Over the course of 3 months, the sitting ability of infants drastically improves. To investigate the mechanisms controlling the development of sitting posture, a single-degree-of-freedom inverted pendulum model was developed.
View Article and Find Full Text PDFIEEE Trans Ultrason Ferroelectr Freq Control
May 2012
The design, fabrication, and characterization of a novel low-frequency meandering piezoelectric vibration energy harvester is presented. The energy harvester is designed for sensor node applications where the node targets a width-to-length aspect ratio close to 1:1 while simultaneously achieving a low resonant frequency. The measured power output and normalized power density are 118 μW and 5.
View Article and Find Full Text PDF