New Materials for Sensors and Actuators: The Role of Nanotechnology

The workshop on New Materials for Sensors and Actuators: The Role of Nanotechnology was hosted by the Intelligent Polymer Research Institute and held at the University of Wollongong February 12th-14th,2002.

The critical role that the developing field of nanotechnology (the ability to synthesise, control and manipulate structures at the nanodimension, <100 nm) is playing in our ability to optimize electrofunctional structures for applications such as polymer electronics, sensing (electronic noses), actuators (artificial muscles) and even electronic textiles was highlighted throughout the meeting.

Strategies for producing nanocomponents based on inherently conducting polymers and/or carbon nanotubes were also discussed and the ability to assemble these into ordered structures (eg. using the synthetic opal approach) was demonstrated.

Materials based on inherently conducting polymers and/or carbon nanotubes are known to possess exceptional properties at the nanodimension. The route to nanocomponents in the inherently conducting polymer area are many and varied as evidenced by the example given by Prof. Jim Johnston who in collaboration with the Intelligent Polymer Research Institute has developed ways to make highly porous conducting polymer coated silicates.

Another important, yet almost forgotten, aspect in the optimization of electrofunctional structures such as described above is the need for novel customized electrolytes. Both the Intelligent Polymer Research Institute in association with Prof. Doug MacFarlane (Monash University) and the Santa Fe Science and Technology group have been working independently in this area while being aware of each others work. A number of separate presentations (Mattes, MacFarlane, Spinks, Ding, Mazurkiewicz) discussed the significant advances that have been made in this area in terms of electrolytic efficiencies attainable and the greatly enhanced stability to electrochemical switching.

In terms of applications of new nanocomponents Prof. Seigmar Roth enthralled the audience with his groups endeavours to construct and demonstrate actuators based on a single carbon nanotube - the worlds smallest artificial muscle!! Seigmar is part of a larger DARPA funded program that is developing strategies to assemble these nanocomponents into macrostructures while retaining the properties of the individual tubes - a truly international research activity later described by Prof. Baughman. Carbon nanotubes and how they can be chemically modified to produce new properties was also the subject of exciting presentations given by Prof. David Officer and Dr. Valerie Barron. The technique used to modify glassy carbon (Dr. Simon Hall) should also prove extremely useful as a synthetic route to functionalising carbon nanotubes.

The polymer actuator technologies described by Prof. Keisuke Oguro and Prof. Toshihiro Hirai were also extremely impressive and should find application in a number of areas. Inherently conducting polymer actuators as described by Prof. Geoff Spinks are already finding applications as the active components in electronic Braille screens, steerable cochlear implants and a wearable actuating glove for rehabilitation. The need for the latter was emphasized in Dr. Tim Scotts excellent address.

The development and use of new materials (especially very small particles and devices) is critical in the emerging field of autonomous monitoring devices as described by Prof. Dermot Diamond. The latter application touches on the area of electronic textiles, an exciting emerging new field as described by Prof. Danilo De Rossi, Dr. Ben Mattes and Prof. Julie Steele. The latter highlighting the use of electronic textiles in sport and rehabilitation. Of course, sensing and actuation in electronic textiles consumes power and Dr. Lynne Samuelson outlined the US Army's ambitious photovoltaic textile program to facilitate such operations.

Applications of inherently conducting polymers as artificial enzymes were also discussed by Dr. Gerry Swiegers describing a highly efficient H2 generation system based on inherently conducting polymers. The biological trend continued in Prof. Dan Nicolau's talk that described the molecular engineering of polymer surfaces to produce protein adhesion and movement, and by Prof. Leon Kane-Maguire who demonstrated the ability of chiral inherently conducting polymers to interact selectively with different hands of amino acids.

The undisputed highlights of the workshop were the inspirational lectures presented by Prof. Alan MacDiarmid (Nobel Prize in Chemistry 2000) and Prof. Graeme Clark (Inventor of the Cochlear Bionic Ear). Both of these "gentlemen of science" have already stamped their mark on the modern scientific era and yet both remain invigorated and enthusiastic in their chosen areas of research. Both of these giants of research continue to work tirelessly pushing the frontiers of research even further. Alan gave an elegant presentation showing us how all-polymer electronic components can be easily constructed for a range of applications. Graeme presented an overview of the development of the Bionic Ear - a cochlear implant now bringing sound to over 30,000
profoundly deaf people.

We are grateful to all who helped in the organization and smooth running of the workshop, to all who participated in lecture and poster presentations, to the University of Wollongong for provision of excellent facilities and to our sponsors.

Professor G.G. Wallace Chairman

Photos

Left to Right: Prof Graeme Clarke, Prof Jim Johnston, Prof Gordon Wallace, Prof Alan MacDiarmid, Prof Ray Baughman.

Left to Right: Dr Trevor Lewis, Prof. Dermot Diamond, Prof. Danillo De Rossi, Prof. Gordon Wallace.