Electrothermal actuators are highly advantageous for microelectromechanical systems (MEMS) due to their capability to generate significant force and large displacements. Despite these benefits, their application in reconfigurable conduction line switches is limited, particularly when employing commercial processes. In DC MEMS switches, electrothermal actuators require electrical insulation between the biasing voltage and the transmission line to prevent interference and maintain the integrity of the switch. This work presents a chevron-type electrothermal actuator utilizing a stack of $\mathrm{S}\mathrm{i}{\mathrm{O}}_2/$ Al thin films on a silicon (Si) structural layer beam to create a DC MEMS switch. The design leverages a thin film Al heater to drive the actuator while the $\mathrm{S}\mathrm{i}{\mathrm{O}}_2$ layer provides electrical insulation, suppressing crosstalk with the Si layer. The electrical contact resistance of a Si-to-Si interface was evaluated by applying a controlled current and measuring the resultant voltage. A low contact resistance of 150 Ω was achieved when an initial contact gap of 2.52 μm was closed using an actuator with an actuation voltage of 1.2 V and a current of 205 mA, with a switching speed of less than 5 ms. Factors such as the contact force, the temperature, and the residual device layer etching angle significantly impact the Si-to-Si contact resistance and the switch’s longevity. The switch withstands a breakdown voltage up to 350 V at its terminal contacts. Thus, it will be robust to self-actuation caused by unwanted voltage contributions, making it suitable for high-voltage and harsh environment applications.

MEMS switches offer great advantages over solid-state and conventional electromechanical switches, including a compact size and high isolation. This paper presents a novel silicon-to-silicon (Si-to-Si) MEMS switch featuring two suspended actuated platforms for DC power switching applications. The proposed design uniquely incorporates dual suspended chevron actuators, enabling bidirectional actuation, enhancing force generation, and improving overall switching performance. Leveraging the robustness of silicon, this Si-to-Si contact switch aims to enhance the reliability of MEMS-based DC power switches. Testing of a fabricated device in the PiezoMUMPs process demonstrated that a 2 μm initial contact gap closes at 1.1 V_DC, with a total actuation power of 246 mW. The switch exhibits a linear voltage–current response up to 5 mA of switching current and achieves a minimum contact resistance of ~294 ± 2 Ω, one of the lowest reported for Si-to-Si contacts. This low contact resistance is attributed to the suspended contact platforms, which mitigate misalignment. The measured response time was 4 ms for turn-on and 2.5 ms for turn-off. This switch withstood a breakdown voltage of up to 376 V across the 2 µm contact gap. Moreover, the 200 nm thick oxide layer separating the actuation and signal lines exhibited breakdown at 183 V. These findings highlight the potential of the switch for high-voltage applications and pave the way for further enhancements to improve its reliability in harsh environments.

This work reports a post-release sputter-metallization process for microelectromechanical systems (MEMS) switches with silicon-to-silicon (Si-to-Si) contacts fabricated by deep reactive ion etching. Platinum (Pt) was selectively deposited on the contacting platforms through a perforated mask. Alternatively, aluminum (Al) was deposited over a thin chromium (Cr) adhesion layer. Electrical measurements showed that Pt enabled a contact resistance on the order of 406 $\Omega$ at a 1 $\mathrm{m}$$\mathrm{A}$ test current, whereas the resistance of Al/Cr coatings decreased from $7.94$ $\mathrm{k}$$\Omega$ at 1 $\mathrm{m}$$\mathrm{A}$ to 270 $\Omega$ at 25 $\mathrm{m}$$\mathrm{A}$, a change that was potentially linked to oxidation of the Al. These results demonstrated successful coating, with uniform top-surface and edge coverage as revealed by energy-dispersive X-ray spectroscopy imaging. Overall, the results indicate that post-release metallization has the potential to improve the operational repeatability of Si-to-Si contact MEMS switches in static and dynamic tests; the findings also point to process refinements to further optimize contact resistance.

This work presents a novel resettable microelectromechanical systems (MEMS)-based circuit breaker (MCB) that utilizes electrostatic actuation for switching and Joule heating for reset functionality. The device integrates a dual air gap and a straight beam suspension structure to enhance contact force, reduce resistance, and improve switching efficiency. Fabricated using the PolyMUMPs process, the MCB features a polysilicon microbridge that achieves stable contact at an electrostatic actuation voltage of approximately 75 V. The circuit-interruption threshold was experimentally determined to be 14 mA–17 mA. Experimental results further validate that the device achieves an average single contact resistance of 162.5 Ω, and a total MCB resistance of 325 Ω, demonstrating its suitability for current-limiting and protection applications.

Microelectromechanical systems (MEMS) circuit breakers offer an attractive pathway toward miniaturized, energy-efficient, and fast-acting electrical protection systems capable of operating in harsh environments. To advance their integration within existing microfabrication frameworks, this paper demonstrates a MEMS-based circuit breaker (MCB) fabricated using the commercial PolyMUMPs process. The device employs electrostatic actuation for contact closure and Joule-heating-induced thermal recovery for reopening, enabling reversible switching. Adhesion-based latching at the contact interface is exploited so that, once closed, the breaker maintains the closed-state without any static hold power. A novel dual-air-gap configuration is implemented to enhance contact force and minimize closed-state resistance, while ensuring negligible leakage current due to high open-state resistance. Experimental characterization reveals an average closed-state contact resistance of $\mathrm {169~\boldsymbol {\Omega } }$ at 140 V and the ability to sustain up to a 100 mA current. Under certain operating conditions, the device exhibits self-unlatching behavior when the conduction current exceeds certain values, corresponding to thermally induced release of the contact interface. This thermally induced reset current that defines the breaker trip point is tunable via the post-actuation gate bias, with the minimum current required to reopen the contacts increasing from 10 mA with no residual gate voltage to 38 mA at a 100 V gate voltage. Temperature-dependent measurements from 20 °C to 170 °C show stable conduction behavior with a temperature coefficient of resistance (TCR) of 414 ppm/°C, supporting operation in elevated-temperature and in harsh-environment applications. [2026-0009]