Ionic polymer-metal composite
Encyclopedia
Ionic polymer–metal composite (IPMC) are synthetic composite materials that display artificial muscle behaviour under an applied voltage. IPMCs are composed of an ionic polymer like Nafion
or Flemion
whose planar surfaces are coated with conductors such as platinum or gold. Under an applied voltage (1–5 V), ion migration and electrostatic repulsion result in a bending actuation. IPMCs are a type of electroactive polymer
.
Alternately, IPMCs act as a smart material
, as applying a mechanical force to the substance will result in a proportional voltage being applied onto the surface.
Bending actuators have seen limited application due to integration into larger devices or stronger actuators. Other limitations include the requirement to maintain ion mobility through hydration or other fluids. Higher voltages result in larger actuations, but voltages above 1.23V will result in electrolysis of water, limiting the useful voltage range.
Nafion
Nafion is a sulfonated tetrafluoroethylene based fluoropolymer-copolymer discovered in the late 1960s by Walther Grot of DuPont. It is the first of a class of synthetic polymers with ionic properties which are called ionomers...
or Flemion
Proton exchange membrane fuel cell
Proton exchange membrane fuel cells, also known as polymer electrolyte membrane fuel cells , are a type of fuel cell being developed for transport applications as well as for stationary fuel cell applications and portable fuel cell applications. Their distinguishing features include lower...
whose planar surfaces are coated with conductors such as platinum or gold. Under an applied voltage (1–5 V), ion migration and electrostatic repulsion result in a bending actuation. IPMCs are a type of electroactive polymer
Electroactive polymers
Electroactive Polymers, or EAPs, are polymers that exhibit a change in size or shape when stimulated by an electric field. The most common applications of this type of material are in actuators and sensors. A typical characteristic property of an EAP is that they will undergo a large amount of...
.
Alternately, IPMCs act as a smart material
Smart material
Smart materials or designed materials are materials that have one or more properties that can be significantly changed in a controlled fashion by external stimuli, such as stress, temperature, moisture, pH, electric or magnetic fields....
, as applying a mechanical force to the substance will result in a proportional voltage being applied onto the surface.
Bending actuators have seen limited application due to integration into larger devices or stronger actuators. Other limitations include the requirement to maintain ion mobility through hydration or other fluids. Higher voltages result in larger actuations, but voltages above 1.23V will result in electrolysis of water, limiting the useful voltage range.
External links
- Shahinpoor, M; Bar-Cohen, Y.; Xue, T.; Simpson, J.O and Smith, J. "Ionic Polymer-Metal Composites (IPMC) as Biomimetic Sensors and Actuators", Proceedings of SPIE's 5th Annual International Symposium on Smart Structures and Materials, 1–5 March, 1998, San Diego, CaliforniaSan Diego, CaliforniaSan Diego is the eighth-largest city in the United States and second-largest city in California. The city is located on the coast of the Pacific Ocean in Southern California, immediately adjacent to the Mexican border. The birthplace of California, San Diego is known for its mild year-round...
. Paper No. 3324-27. - S. Nemat-Nasser and C. Thomas, "Electroactive Polymer (EAP) Actuators as Artificial Muscles – Reality, Potential and Challenges", Ionomeric Polymer-metal Composites, edited by Bar-Cohen, SPIE, Chap. 6 [139 2001.]
- IPMC Actuator