Research on the Fabrication of Ultrafast Micro-thermocouples Using Meniscus-Confined Electrodeposition

Abstract

Precise microscale temperature sensing is important for evaluating the thermal reliability of microelectromechanical systems (MEMS), microfluidic devices, and other miniaturized systems. However, conventional lithography and vacuum-deposition-based fabrication methods are inherently limited in constructing freestanding three-dimensional (3D) thermocouple architectures. In this work, a maskless 3D additive manufacturing method based on meniscus-confined electrodeposition (MCED) is developed for the direct fabrication of Cu–Zn micro-thermocouples and sensor arrays. By spatially confining the electrochemical deposition process within a microscale meniscus, Cu and Zn microstructures can be sequentially deposited along programmed trajectories to form freestanding bimetallic thermocouple junctions without post-annealing. The fabricated Cu–Zn micro-thermocouple exhibits a response time of 7.8 ms and a Seebeck coefficient of 4.3 μV/°C, showing good agreement with the simulated thermoelectric response. A 3 × 3 micro-thermocouple array is further demonstrated for multipoint temperature measurement of a localized heat source. These results demonstrate the feasibility of MCED for the direct fabrication of spatially configurable micro-thermocouple devices and provide a flexible approach for localized and dynamic thermal sensing in miniaturized systems.