Novel Test Fixture for Characterizing MEMS Switch Microcontact Reliability and Performance

In microelectromechanical systems (MEMS) switches, the microcontact is crucial in determining reliability and performance. In the past, actual MEMS devices and atomic force microscopes (AFM)/scanning probe microscopes (SPM)/nanoindentation-based test fixtures have been used to collect relevant microcontact data. In this work, we designed a unique microcontact support structure for improved post-mortem analysis. The effects of contact closure timing on various switching conditions (e.g., cold-switching and hot-switching) was investigated with respect to the test signal. Mechanical contact closing time was found to be approximately 1 μs for the contact force ranging from 10–900 μN. On the other hand, for the 1 V and 10 mA circuit condition, electrical contact closing time was about 0.2 ms. The test fixture will be used to characterize contact resistance and force performance and reliability associated with wide range of contact materials and geometries that will facilitate reliable, robust microswitch designs for future direct current (DC) and radio frequency (RF) applications.

Assistive technology for promoting choice behaviors in three children with cerebral palsy and severe communication impairments

A technology-based program to promote independent choice behaviors by three children with cerebral palsy and multiple disabilities was assessed. The program was based on learning principles and assistive technology (i.e., customized input devices/sensors, personal computers, screening of preferred stimuli according to a binomial criterion). The first purpose of the present study was to provide the participants with a new set-up of assistive technology and to allow them to choose among three categories (i.e., food, beverage and leisure), and to request a specific item out of four in each category, adopting a procedure that minimized (according to a conditional probability criterion) unintentional choices. The second aim of the study was to carry out the effects of the program on detectable mood signs (i.e., happiness index). The study was conducted according to an ABAB sequence with a subsequent post intervention check for each participant. The results showed an increase of engagement and of the happiness index during intervention phases. Psychological as well as educational implications were discussed.