A Soft Future?

1. A Soft Future? Dr. Paul Meredith Soft Condensed Matter Physics Group & Centre for Biophotonics & Laser Science University of Queensland School of Physical Sciences www.softsolids.physics.uq.edu.au

2. Theme Soft Electronics – Reality or Pipe-Dream? Plastic Logic©

3. Outline • What are “soft-solids” and what is “soft-electronics”? • “The Silicon Age” • “The Soft Age” – a revolution in functional materials and high technology • Nanotechnology – “scale without size” • The best of both worlds – nano-engineering of functional soft solids (nano-bio link) • SCM Physics @ UQ • electrically conducting biomaterials • new synthetic conducting plastics • plastic solar cells • nano-engineering of support structures • Summary – what can we really expect from the functional soft-solids revolution?

4. What are “Soft Solids”?

5. Why “Soft Solids”? • Soft-solids (polymers especially) are cheap to manufacture, relatively easy to process, can have better environmental profiles than “hard solids”, are mechanically flexible and robust .... but (until recently) have lacked “functionality” $$$$$

6. The Silicon Age (1947 onwards) IBM Archive© 1947 – the 1st transistor (Ge point contact) 1948 – the 1st junction transistor (Ge) John Bardeen Walter Brattain William Shockley (BELL Labs)

7. Inorganic Semiconductors • The basic ingredient for all high technology devices and products • The advantages • fast • relatively dependable • versatile • technology is in place – they work! • The disadvantages • costly • very difficult to process (UHV equipment and photolithography) • some compound SCs have horrible environmental profile (e.g. GaAs) • limited stock of some • delicate & no mechanical flexibility

8. The “Soft Age” (1977 to ......?) A revolution in functional materials for high technology? • The 2000 Nobel Prize for Chemistry was awarded for the discovery of metal-like electrical conductivity in iodine-doped polyacetylene • Prior to this discovery (Shirakawa, Heeger, MacDairmid), it was thought that organic polymers could not conduct electricity in the solid state • The “Soft Age” was born Sov and Alan MacDairmid

9. The “Soft Age” (1977 to ......?) • Explosion in “functional” soft-solids research (small molecule and large molecule organic electronics) • Wild predictions of high tech and low tech applications – soft-solid related material benefits plus electrical (semiconducting) functionality • IBM, Lucent, Philips, Seiko Epson, HP all have major organic electronics programs plastic memory smart textiles biosensors electronic ink organic solar cells 1,888 Transistors! A thin film conducting polymer transistor and “soft-circuitry” – arrays of these transistors on a flexible polymer sheet Light emitting polymer displays – thin, flexible screens with 180˚ view Plastic Logic©

10. The “Soft Age” (1977 to ......?) • Ever increasing numbers of organic electronic (soft-electronic) materials (small and large molecules) Plus “organic molecular crystals” like the oligo-acenes

11. Nanotechnology “scale without size” © www.wag.caltech.edu © http://www.unibas.ch/phys-meso

12. Nano-engineering of Functional Soft Solids • Many “new” nanotechnologies will contain soft materials • Nano-biotechnology attempts to nano-engineer biomaterials (DNA electronics etc.) • The first realistic nano-engineered soft solids will probably be micro or nano patterned conducting polymers © http://www.rhk-tech.com/hall

13. SCM Physics @ UQ – What are we doing to help (in a small way) fuel this revolution? • Several programs concerned with understanding and utilising functional soft solids • Heavy focus on biomaterials as well as synthetic polymers • electrically conducting biomaterials • new synthetic conducting plastics • plastic solar cells • nano-engineering of support structures

14. 1. A Biomaterial Sensor A melanin sensor

15. EDX Scan Line 50nm 2. Novel Routes to Synthetic Conducting Polymers (Ion Implantation) CHEAP, CONDUCTING PLASTICS – FROM CONVENTIONAL INSULATING PLASTICS? • Patterning Strategies: • conventional and unconventional nano-lith • inkjet nano-printing of the metal + implantation with a broad beam • focused ion-beam writing

16. 3. Plastic Solar Cells Current WORLD RECORD ~5% (PCE) (c.f. Commercial Silicon cells ~ 15%) nano-crystals in a conducting polymer matrix This cell produces a WHOPPING 20mA

17. 4. Nano-engineering of Support Structures – scale without size! • Create support structures and electrodes which have a very large internal surface area (nano-engineering) – provide a large surface for attachment of functional organic molecules and enhance properties such as charge transport and photon capture R. Vogel R6G/titania nano- composite formed into a micro-donut (microphotonics) K. Teo, U. Camb A carbon nanotube field – potential solar cell material A nanostructured titania support/electrode

18. Summary – what can we really expect from the “soft-electronics” revolution? We at UQ Physics are trying to do our bit: - functional biomaterials - plastic solar cells - new (cheap), patternable synthetic conducting polymers

21. Acknowledgements • E. Moore (UQ Postdoc) • D. Blake (UQ / CSIRO PhD) • M. Harvey (UQ PhD)* • J. Riesz (UQ Hons) • S. Subianto (QUT PhD)**** • E. Tavenner (UQ PhD) • L. Tran (UQ Postdoc)** • R. Vogel (UQ PhD Chem / Postdoc)* • A. Watt (UQ PhD)* • H. Rubinsztein-Dunlop (CBLS)* • P. Bernhardt (UQ Chem) • P. Evans (ANSTO, Lucas Heights) • A. Hamilton (UNSW) • M. Lu (UQ Chem Eng)*** • A. Micolich (UNSW) • R. McKenzie (UQ)** • B. Powell (UQ)*** • B. Reguse (CSIRO, TIP) • T. Sarna (Jagiellonian University, Poland) • K. Teo (Cambridge University, UK) • G. Wills (QUT)**** Funding: ARC Discovery (DP0210458, DP0345309) ARC Linkage (LE0239044) UQ (ECR, RIBG, RDGS, NSSF) ANSTO (2002 & 2003) Procter & Gamble Centre for Biophotonics & Laser Science

22. The End “For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled” Dick Feynman