Day 2 :
University of Bolton, UK
Time : 09:00-09:25
Elias Siores is the Provost and Director of Research and Innovation, Bolton University. Educated in the UK (BSc, MSC, MBA, PhD) and pursued his academic career in Australia (Sydney, Brisbane and Melbourne) and Asia (Hong Kong, Dong Guan) before returning to Europe (UK) as a Marie Curie Fellow. He is also President, Board of Governors, TEI – Athens and Director of Innovation, FibrLec Ltd. His R&D work concentrated on advancing the science and technology in the field of automated Non-Destructive Testing and Evaluation including Ultrasound, Acoustic Emission, and Microwave Thermography. His recent R&D work focuses on Smart / Functional Materials and Systems development. In this area, he has developed Electromagnetic, Electrorheological, Photovoltaic and Piezoelectric Smart Materials based Energy Conversion Systems for Renewable Energy, Medical, Health Care and Wearable Devices. He has published over 300 publications including 8 Patents . He has been a member of editorial boards of international journals and a Fellow of IOM, TWI, IEAust, SAE and WTIA. He has served on Board of Directors of a number of research centres worldwide including UK, Australia, Singapore and Hong Kong, all associated with the Bio-Nano-Materials field. He is a member of the Parliamentary Scientific Committee and has received 15 international awards in his career for R&D and innovation achievements.
For energy harvesting from human movement, fibre based electrical power generators are highly desirable as they are light weight and comfortable and look no different from the conventional fabrics. The conjunction of piezoelectric materials in fibres and therefore fabrics offers a simple route for the building of soft piezoelectric generators. The flexible textile structures can themselves be designed so as to provide piezoelectric output on low levels of strains and loadings while providing high fatigue resistance under a large number of variable mechanical deformation and loading cycles. In this work, we demonstrate “3D spacer” technology based all-fibre piezoelectric fabrics as power generators and energy harvesters (Figure 1(a)). The single step knitted structure consisting of high β-phase (~80%) piezoe-lectric PVDF produced using conventional melt spinning under high electric field (0.6 MV/m) are knitted together with Ag coated PA66 yarns acting as the top and bottom electrodes. The novel and unique textile structure provides an output power density in the range of 1.10-5.10 μWcm-2 at applied impact pressures in the range of 0.02-0.10 MPa, providing significantly higher power outputs and efficiencies over the existing 2D woven and nonwoven piezoe-lectric structures (Figure 1(b)). The all fibre piezoe-lectric fabric possesses the advantage of efficient charge collection due to intimate contact of electrodes and uniform distribution of pressure on the fabric surface, leading to enhanced performance. Furthermore, an substantial increase in piezoelectric output of the PVDF yarns has been achieved using ZnSnO3 based perovskite which has doubled the piezoelectric constant from 60 pm/V to nearly 130 pm/V. Bearing all these merits in mind, we believe our method of producing large quantities of high quality piezoelectric yarn and piezoelectric fabric provides an effective option for the development of high performance energy-harvesting textile structures for electronic devices that could be charged from ambient environment or by human movement. Fur-thermore, via the creation of hybrid photovoltaic films and fibres, energy can be captured from solar radiation and used where the mechanical impetus is absent. The high energy efficiency, mechanical dura-bility and comfort of the soft, flexible and all-fibre based power generator is highly attractive for a variety of potential applications such as wearable electronic systems and energy harvesters charged from ambient environment or by human movement.
University of Oldenburg, Germany
Keynote: Consequences of the Physical Foundation of the Exponent 3/2 in Pyramidal/Conical (Nano)Indentations for the Mechanical Parameters and for Daily Life
Time : 09:25-09:50
Gerd Kaupp has completed his PhD at the age of 24 years from Würzburg University and postdoctoral studies from Iowa State, Lausanne, and Freiburg University. He held a full-professorship till 2005 in Oldenburg, Germany, and he privately continues his research on AFM on rough surfaces (since 1988), the as yet better resolving sub-diffraction limit microscopy also for non-fluorescing materials, even rough ones, of all types (resolution <10 nm, since 1995), and nano-indentations (since 2000). He has published more than 300 papers in renowned journals and has been serving as an editorial board member of several scientific journals.
The recently published physical foundation of the experimental exponent 3/2 for pyramidal indentations (validated since 2003 by the author, while ISO still dictates exponent 2 from textbooks and work of half a century) on the depth h in relation to normal force FN creates dilemma for industry and security agencies. They have to obey ISO standards with legal character, even though physics tells differently. Even NIST (US member of ISO) published 6 new mechanical parameters in a tutorial that continues distributing "false physics" using exponent 2. We must thus urgently try to change that situation, because falsely calculated mechanical properties severely harm all public in daily life, in medicine (implants with bone cements), and techniques. Material's compatibilities (including solders) and mechanical stress are ubiquitous, to name a few. Material's failures have been claimed as fatigue of materials, rather than calculations against physics. Errors are with finite element simulations always resulting with exponent 2, unnoticed phase transitions with their onset and energies, or surface effects. These are only recognized when applying exponent 3/2, but not by polynomial curve fittings, or "best exponent iterations". Almost all mechanical parameters require re-deduction on the basis of the correct exponent. ISO-hardness H and ISO-modulus Er are doubly flawed: they rely on the false exponent against physics and they often unconsciously characterize after phase transitions. All materials require genuine physical characterization! Thus, physical H, Er, and other parameters (adhesion energy, etc.) have to be deduced. This will be addressed upon, and we will find unexpected applications.