Micro deposition method: a novel fabrication method for ionic polymer metallic composites

Wallmersperger

Behavior and Mechanics of Multifunctional and Composite Materials 2008

et al. 2008

Ionomeric polymer transducers have received considerable attention in the past ten years due to their ability to generate large bending strain and moderate stress at low applied voltages. Ionic polymer transducers consist of an ionomer, usually Nafion, sandwiched between two electrically conductive electrodes. Recently, a novel fabrication technique denoted as the direct assembly process (DAP) enabled controlled electrode architecture in ionic polymer transducers. A DAP transducer usually consists of two high surface area electrodes made of uniform distributed particles sandwiching an ionomer membrane. Further enhancements to the DAP enabled sub-micron control of the electrode architecture. In this study a previously developed finite element model, capable of simulating ionic polymer transducers with high surface area electrodes is used to study the effect of electrode architecture on the actuation performance due to a unit volt step input. Four architectures are considered: Agglomerate, Gradient, Random, and Lines. The four architectures are simulated for low particle loading and high particle loading. The agglomerate presents the case of badly dispersed metal particles in the electrode. Simulation results demonstrate that particle aggregation reduces the actuation performance on an IPT. The Gradient simulates an IPT built using an Impregnation-Reduction method. The Gradient is compared to a randomly distributed electrode which represents an IPT built using the DAP method. Simulation results demonstrate that the DAP built IPT outperforms the one built using the impregnation-reduction method. Finally line architecture is simulated and results demonstrate that it outperforms random architecture especially at high particle loading.

Section: Charge Density and Electromechanical Transductionmentioning

confidence: 99%

“…The numerical model can capture the chemo-electric behavior in the polymer and also the electrode region. In a recent development to the DAP fabrication process, Griffith et al [10] demonstrated that the electrode could be printed with a resolution of 2µm. This enables control on particle distribution.…”

Section: Introductionmentioning

confidence: 99%

High surface area electrodes in ionic polymer transducers: numerical and experimental investigations of the chemo-electric behavior

Wallmersperger

Behavior and Mechanics of Multifunctional and Composite Materials 2008

et al. 2008

“…Therein, layers of Nafion dispersions are dispersed into silicone casts and the solvent in the dispersion is allowed to evaporate away. A micro deposition method employing inkjet technology was also developed based on the use of Nafion dispersions in [25]. By contrast, the 3D printing method proposed here is a fused filament AM technique.…”

Section: Introductionmentioning

confidence: 99%

Fused filament 3D printing of ionic polymer-metal composites (IPMCs)

Carrico

Traeden

Aureli

et al. 2015

Smart Mater. Struct.

118

109

This paper describes a new three-dimensional (3D) fused filament additive manufacturing (AM) technique in which electroactive polymer filament material is used to build soft active 3D structures, layer by layer. Specifically, the unique actuation and sensing properties of ionic polymer-metal composites (IPMCs) are exploited in 3D printing to create electroactive polymer structures for application in soft robotics and bio-inspired systems. The process begins with extruding a precursor material (non-acid Nafion precursor resin) into a thermoplastic filament for 3D printing. The filament is then used by a custom-designed 3D printer to manufacture the desired soft polymer structures, layer by layer. Since at this stage the 3D-printed samples are not yet electroactive, a chemical functionalization process follows, consisting in hydrolyzing the precursor samples in an aqueous solution of potassium hydroxide and dimethyl sulfoxide. Upon functionalization, metal electrodes are applied on the samples through an electroless plating process, which enables the 3D-printed IPMC structures to be controlled by voltage signals for actuation (or to act as sensors). This innovative AM process is described in detail and the performance of 3D printed IPMC actuators is compared to an IPMC actuator fabricated from commercially available Nafion sheet material. The experimental results show comparable performance between the two types of actuators, demonstrating the potential and feasibility of creating functional 3D-printed IPMCs.

“…A different method for applying the DAP was used in [57] where the electrodes were formed using Micro deposition. It gave more accuracy in the architecture of the electrode compared to manually dispersing the solution.…”

Section: Electrode Fabrication Methodsmentioning

confidence: 99%

3D Printing of IPMC Actuators Based on the Direct Assembly Method. (c2022)

Sarkis¹

Ionic polymer metal composites are a type of electroactive polymers, they are composed of an ionomer membrane sandwiched between two conducting high surface area electrodes. They act as an actuator under the application of a relatively small applied electric voltage in the order of 1 to 4V, producing large strains compared to other actuators. The middle membrane acts as an eclectic insulator that allows ions to move from one electrode to the other. The negatively charged high surface area electrode attracts the positively charged mobile cations resulting in actuation. IPMCs also operate in sensing mode by generating electricity when subject to mechanical deformations. This versatility in operation makes them good candidates for a number of complex applications including biomimetics, micro-robotics, and medical catheters. These different application demand complex geometries and high level of performance. The electrode morphology has been proven to play a critical role in the performance of IPMCs. In this thesis, the process of 3D printing the IPMC along with the electrodes using FDM 3D printing is investigated. Our method will enable the 3D printing of both: the Nafion insulating center layer, and a Ruthenium Dioxide-Nafion mixture composing the high surface area electrode. The electrodes performance will be evaluated against the traditional impregnation reduction method for electrode plating applied to a 3D printed membrane. Also, the performance of a membrane made by hot-pressing Nafion pellets, a traditional Nafion membrane fabrication method, will be used to validate the 3D printing process. The 3D printed electrodes achieved a strain of 3.71E-4 which was lower than the strain of impregnation reduction method at 1.14 E-3. This was attributed to excessive flaking and poor mixing of the Ruthenium Dioxide particles in the polymer matrix.