Fabrication of Nanoporous Co Actuators by a Chemically Dealloying Approach

As a prominent subset of electrochemical actuators, nanoporous (NP) metal actuators have garnered significant attention owing to their low energy consumption, facile fabrication, rapid response, tunable dimensions, and excellent corrosion resistance. Currently, the majority of NP-metal actuators are predominantly based on precious metals. While these precious metal-based actuators exhibit superior actuation performance, their widespread application is hindered by high costs and limited availability of raw materials. This study introduces an NP-Co actuator fabricated through a one-step chemical dealloying process, utilizing cost-effective metals, Al and Co, as starting materials. The electrochemical actuation performance of the NP-Co actuator demonstrates remarkable competitiveness when compared to other metal actuators, particularly those based on precious metals. The maximum strain amplitude of the NP-Co actuator, measured using the chronoamperometry (CA) method, reaches 0.54%, surpassing the reported values for NP-Au, NP-Pt, and NP-Ag actuators. Furthermore, the NP-Co actuator exhibits a rapid response to electrical stimulation, with a maximum strain rate of 1.82 × 10–4 s–1, exceeding those of NP-Pt, NP-Au, NP-Pd, NP-Ni, NP-Cu, and NP-Ag actuators. With its low cost, ease of processing, low energy consumption, fast response, and substantial strain, the NP-Co actuator emerges as a promising alternative to precious metal-based actuators, offering significant potential for diverse applications.