All‐Solid‐State Electro‐Chemo‐Mechanical Actuator Operating at Room Temperature. (7th October 2020)

• Record Type: Journal Article
• Authors: Makagon, Evgeniy; Wachtel, Ellen; Houben, Lothar; Cohen, Sidney R.; Li, Yuanyuan; Li, Junying; Frenkel, Anatoly I.; Lubomirsky, Igor
• Is Part Of: Advanced functional materials. Volume 31:Number 3(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-10-07
• Subjects: actuation -- chemo‐mechanics -- micro‐electro‐mechanical systems -- oxygen‐ion conductors; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202006712
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Dimensional change in a solid due to electrochemically driven compositional change is termed electro‐chemo‐mechanical (ECM) coupling. This effect causes mechanical instability in Li‐ion batteries and solid oxide fuel cells. Nevertheless, it can generate considerable force and deformation, making it attractive for mechanical actuation. Here a Si‐compatible ECM actuator in the form of a 2 mm diameter membrane is demonstrated. Actuation results from oxygen ion transfer between two 0.1 µ m thick Ti oxide\Ce0.8 Gd0.2 O1.9 nanocomposite layers separated by a 1.5 µ m thick Ce0.8 Gd0.2 O1.9 solid electrolyte. The chemical reaction responsible for stress generation is electrochemical oxidation/reduction in the composites. Under ambient conditions, application of 5 V DC produces actuator response within seconds, generating vertical displacement of several µm with calculated stress ≈ 3.5 MPa. The membrane actuator preserves its final mechanical state for more than 1 h following voltage removal. These characteristics uniquely suit ECM actuators for room temperature applications in Si‐integrated microelectromechanical systems. Abstract : A self‐supported, electro‐chemo‐mechanical membrane actuator, driven by room temperature oxidation/reduction reactions, is developed and characterized. Specifically designed, nanocomposite working bodies provide high oxygen ion diffusivity and large electrochemical volume change. The actuator pseudo‐piezoelectric coefficient is comparable to that of popular lead‐free piezoelectrics, thereby demonstrating that electro‐chemo‐mechanics could provide a promising new approach in the Si integrated micro actuation field.