Preface

It is a great honor to serve as editor for this historic volume on electroactive ionic polymers and in particular ionic polymer metal composites or IPMCs as smart multi-functional polymeric actuators, sensors and energy harvesters, among others. I can proudly proclaim that I have brought together in this volume the leading researchers in the world on various aspects of this amazing biomimetic robotic electronic material that play quite a role in the future of electroactive polymers and smart multi-functional materials.

IPMC is a class of electroactive polymers that can be both actuator and sensor. By applying voltage it exhibits large deformation, which is why it is known as artificial muscle and, on the other hand, it acts as a smart material that can sense mechanical bending by creating proportional voltage. While other strain sensors require a power source to work, the IPMC sensors not only do not require power, but also they can create voltage and power that makes them a potential candidate for battery-less sensors. Conversely, an applied small voltage or electric field can induce an array of spectacularly large deformation or actuation behaviors in IPMCs, such as bending, twisting, rolling, twirling, steering and undulating.

My vision of the future of IPMC artificial muscles may be summarized below in terms of both medical and industrial applications. Note that IPMCs are excellent sensors that generate huge outputs in terms of millivolts, which can be employed for the sensing, transduction and harvesting of energy from wind or ocean waves. These unique materials work perfectly well in a wet environment and thus they are excellent candidates for medical applications. These might range from endovascular steerers and stirrers to enable navigation within the human vasculature; use as deep brain stimulators or employed in flat diaphragm micropumps for precision drug delivery, glaucoma and hydrocephalus; artificial muscles for the surgical correction of ptosis (drooping eyelid syndrome); ophthalmological and vision improvement applications; artificial muscles to assist a failing heart; correction of facial paralysis, facioscapulohumeral and other applications in muscular dystrophy; to mediate the control of drainage or flow within the human body; and myriad additional purposes. On the industrial side, due to the fact that the IPMCs are excellent sensors and low-voltage actuators, they can be used for both sensing and simultaneous actuation in many engineering applications. In the sensing mode they have a very good bandwidth to sense low as well as high frequencies, in contrast to piezoelectric materials such as PZT (Lead Zirconate Titanate) or lithium niobate, which are only suitable for high-frequency sensing. Two emerging visions of the future are to see IPMCs heavily utilized in atomic force microscopes as novel and dynamic probes in scanning probe microscopy, as well as robotic surgery to facilitate the conveyance of specific haptic, force, tactile and impedance feedback to surgeons. IPMCs as active substrate and micro-pillars may be used to monitor nano-bio and cellular dynamics in real time.

These two volumes on IPMCs provide a broad coverage of the state of the art and recent advances in the field with detailed information on the characteristics and applications of these materials by some of the world's leading experts on various characterizations and modeling of IPMCs. This volume contains 27 chapters to present a thorough coverage of all properties and characteristics of IPMCs. Chapter 1 covers the fundamentals of IPMCs, Chapter 2 covers optimal manufacturing of IPMCs, Chapter 3 discusses graphene-based IPMCs, Chapter 4 describes what happens to IPMC electrode interfaces and their effects on actuation and sensing, Chapter 5 presents step-by-step modeling of IPMCs using the multiphysics package of Comsol, Chapter 6 describes IPMCs with electrochemical electrodes, Chapter 7 presents electromechanical distributed modeling of IPMCs while Chapter 8 discusses modeling for engineering design of IPMC devices and Chapter 9 covers electric energy storage using flexible IPMC capacitors, Chapter 10 models the environmental dependency of IPMCs’ actuation and sensing dynamics, Chapter 11 discusses the precision feedback/feedforward control of IPMC dynamics while Chapter 12 covers the design, testing and micromanipulation of IPMC microgrippers, Chapter 13 discusses the phenomenon of spatially growing waves of snake-like robots and natural generation of biomimetic swimming motions. Volume 1 of the two volumes on IPMCs ends here with Chapter 13 and Volume 2 starts with Chapter 14. Chapter 14 covers underwater sensing of impulsive loading of IPMCs, Chapter 15 presents a design of a micropump for drug delivery employing IPMCs, Chapter 16 presents the modeling and characterization of IPMC transducers, Chapter 17 discusses IPMCs as postsilicon transducers for the realization of smart systems and Chapter 18 covers micromachined IPMC actuators for biomedical applications, Chapter 19 presents recent advances in IPMC self-sensing while Chapter 20 describes the continuum multiphysics theory for IPMCs, Chapter 21 covers multiphysics modeling of non-linear plates made with IPMCs, Chapter 22 describes the applications of IPMCs to dexterous manipulation and haptic feedback/tactile sensors for minimally invasive robotic surgery, Chapter 23 covers IPMCs as soft biomimetic robotic artificial muscles, Chapter 24 describes a family of ionic electroactive actuators with giant electromechanical responses while Chapter 25 describes the multiphysics modeling and simulation of dynamics sensing in IPMCs with applications to soft robotics, and finally Chapter 26 presents a comprehensive review on electroactive paper actuators.

I am hoping that the collection of these chapters by the leading authorities on IPMCs will appeal to readers from chemistry, materials science, engineering, physics and medical communities interested in both IPMC-related materials and their applications.

Mohsen Shahinpoor

Orono, Maine, USA