Intermittent failure mechanism and stabilization of microscale electrical contact

Abstract

The stability and lifetime of electrical contact pose a major challenge to the performance of microelectro-mechanical systems (MEMS), such as MEMS switches. The microscopic failure mechanism of electrical contact still remains largely unclear. Here conductive atomic force microscopy with hot switching mode was adopted to simulate the asperity-level contact condition in a MEMS switch. Strong variation and fluctuation of current and adhesion force were observed during 10,000 repetitive cycles, exhibiting an “intermittent failure” characteristic. This fluctuation of electrical contact properties was attributed to insulative carbonaceous contaminants repetitively formed and removed at the contact spot, corresponding to degradation and reestablishment of electrical contact. When contaminant film was formed, the contact interface became “metal/carbonaceous adsorbates/metal” instead of direct metal/metal contact, leading to degradation of the electrical contact state. Furthermore, a system of iridium/graphene on ruthenium (Ir/GrRu) was proposed to avoid direct metal/metal contact, which stabilized the current fluctuation and decreased interfacial adhesion significantly. The existence of graphene enabled less adsorption of carbonaceous contaminants in ambient air and enhanced mechanical protection against the repetitive hot switching actions. This work opens an avenue for design and fabrication of microscale electrical contact system, especially by utilizing two-dimensional materials.

MEMS Switch Realities: Addressing Challenges and Pioneering Solutions

“…This parameter plays a pivotal role in various MEMS applications, influencing the reliability and precision of the device operation. Engineers meticulously optimize the release voltage by considering factors such as electrode geometry, distance between electrodes, and material properties [45,46]. Striking the right balance in the release voltage is essential to avoid issues like excessive power consumption, potential damage, or incomplete release, ensuring the optimal performance and longevity of electrostatic MEMS devices.…”

Deep understanding of the dependence between capillary adhesion behavior and meniscus Kelvin radius or interface micromorphology

“…On one aspect, the capillary force yields unfavorable consequences. The adhesion prompted by capillary phenomenon introduces friction predicament at the interfaces of micro-devices, which has emerged as a pivotal contributor to the malfunction of MEMS devices 10,11 . On the other hand, capillary force can be applied to micro grasping to realize fine operations such as nanoassembling and nano-processing [12][13][14] .…”

Simulation of electrical contact wear on the rough surfaces of ultra-high-voltage transmission line fittings

“…Many studies have been conducted to investigate the problem of electrical contact wear. [1][2][3][4][5] Electrical contact wear is a complex process involving several physical changes and chemical reaction interaction including friction, temperature rises, mechanical wear, and oxidation. Azevedo et al 6 performed experimental research on the wear behaviors of electric contact friction and established the relationship between material loss and peeling of the hard phase produced by the oxidation of the friction pair surface.…”