The surface of a medical implant is required to interact favourably with ions, biomolecules and cells in vivo , commonly resulting in the formation of the extracellular matrix. Medical grade Ti6Al4V alloy is widely used in orthopaedic and dental applications for bone replacement due to its advantageous mechanical properties and biocompatibility, which enhances the adhesion between native tissue and the implanted material. In this study, chemical and thermal modi fi cation of a medical-grade Ti6Al4V alloy were performed to enhance electrostatic interactions at the alloy surface with a synthetic peptide, suitable for conferring drug release capabilities and antimicrobial properties. The modi fi ed surfaces exhibited a range of topographies and chemical compositions depending primarily on the treatment temperature. The surface wetting behaviour was found to be pH-dependent, as were the adhesive properties, evidenced by chemical force titration atomic force microscopy. the surface properties were not reported. This study aims to show how the thermal oxidation and chemical treatment with H 2 O 2 of a medical-grade Ti6Al4V surface can a ff ect its chemical composition and topography in

Mechanotransduction is of fundamental importance in cell physiology, facilitating sensing in touch and hearing as well as tissue development and wound healing. This study used an impedance sensor to monitor the effective resistance and permittivity of artificial tissues, alginate hydrogel with encapsulated fibroblasts, which were kept viable through the use of a bespoke microfluidic system. The observed transient impedance responses upon the application of identical compressive normal loads differed between acellular hydrogels and hydrogels in which fibroblasts were encapsulated. These differences resulted from changes in the conductivity and permeability of the hydrogel due to the presence of the encapsulated fibroblasts, and transient changes in ion concentrations due to mechanotransduction effects. shows a linear stress-strain relationship

Investigation of micro-textures and strengths of microwave heated samples of lunar simulant JSC-1A under different input powers Conference or Workshop Item How to cite: Lim, S.; Bowen, J.; Anand, M.; Degli-Alessandrini, G.; Levin Prabhu, V.; Morse, A.D. and Cowley, Aidan (2020). Investigation of micro-textures and strengths of microwave heated samples of lunar simulant JSC-1A under different input powers. In: European Lunar Symposium (ELS) 2020, 12-14 May 2020, Virtual.

Microwave heating experiment of lunar simulant (JSC-1A) using a bespoke industrial microwave apparatus Conference or Workshop Item How to cite: Lim, Sungwoo; Jiang, Yachen; Morse, Andrew; Anand, Mahesh; Bowen, James and Holland, Andrew (2019). Microwave heating experiment of lunar simulant (JSC-1A) using a bespoke industrial microwave apparatus. In: European Lunar Symposium (ELS) 2019, 21-23 May 2019, Manchester, United Kingdom.

Objective To modify the non-porous surface membrane of a tissue-engineered laryngeal scaffold to allow effective cell entry. Methods The mechanical properties, surface topography and chemistry of polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane were characterised. A laser technique introduced surface perforations. Micro computed tomography generated porosity data. Scaffolds were seeded with cells, investigated histologically and proliferation studied. Incubation and time effects were assessed. Results Laser cutting perforated the polymer, connecting the substructure with the ex-scaffold environment and increasing porosity (porous, non-perforated = 87.9 per cent; porous, laser-perforated at intensities 3 = 96.4 per cent and 6 = 89.5 per cent). Cellular studies confirmed improved cell viability. Histology showed cells adherent to the scaffold surface and cells within perforations, and indicated that cells migrated into the scaffolds. After 15 days of incubation, scanning electron microscopy revealed an 11 per cent reduction in pore diameter, correlating with a decrease in Young's modulus. Conclusion Introducing surface perforations presents a viable method of improving polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane as a tissue-engineered scaffold.

The reference cantilever method is shown to act as a direct and simple method for determination of torsional spring constant. It has been applied to the characterization of micropaddle structures similar to those proposed for resonant functionalized chemical sensors and resonant thermal detectors. It is shown that this method can be used as an effective procedure to characterize a key parameter of these devices and would be applicable to characterization of other similar MEMS/NEMS devices such as micromirrors. In this study, two sets of micropaddles are manufactured (beams at centre and offset by 2.5 μ m) by using LPCVD silicon nitride as a substrate. The patterning is made by direct milling using focused ion beam. The torsional spring constant is achieved through micromechanical analysis via atomic force microscopy. To obtain the gradient of force curve, the area of the micropaddle is scanned and the behaviour of each pixel is investigated through an automated developed code. The experimental results are in a good agreement with theoretical results.

In this chapter we have sought to provide readers with an overview of in vivo techniques currently used for the imaging of biomineralisation materials. To achieve this we have provided a background of what biomineralisation entails and why there is a need for biomaterials. Furthermore, we have briefly reviewed some of the in vitro techniques used for the basic understanding of mineralisation events and the prediction of how the materials may behave in vivo. For the latter we have attempted to guide the reader through how the techniques work and how they are used to monitor the biomineralisation process, with focus on integration of the implanted material with its surroundings. The technologies described here are constantly being updated, guided by the complexity in monitoring needs. We therefore advise the reader to update this list regularly.

New engineered materials have critical applications in different fields in medicine, engineering and technology but their enhanced mechanical performances are significantly affected by the microstructural design and the sintering process used in their manufacture. This work introduces (i) a methodology for the calculation of the full deflection profile from video recordings of bending tests, (ii) an optimisation algorithm for the characterisation of Young's modulus, (iii) a quantification of the effects of optical distortions and (iv) a comparison with other standard tests. The results presented in this paper show the capabilities of this procedure to evaluate the Young's modulus of highly stiff materials with greater accuracy than previously possible with bending tests, by employing all the available information from the video recording of the tests. This methodology extends to this class of materials the possibility to evaluate both the elastic modulus and the tensile strength with a single mechanical test, without the need for other experimental tools.

19 In this paper, the viability of directly exposing thin films of liquid poly(dimethylsiloxane) (PDMS) to elec20 tron beam (e-beam) irradiation using e-beam lithographic methods for the purpose of creating perma21 nent micro-scale components has been investigated. By exposing 1.1 lm thickness PDMS films to 22 doses in the range 10–50,000 lC/cm, it was discovered that the structure of the resultant film exhibits 23 four distinct phases, depending upon the exposure dose. These phases were manifested in both the resul24 tant Young’s modulus and thickness of the developed film. It was found that there is a critical dose 25 whereupon the resultant film undergoes solidification and adheres to the counter surface sufficiently 26 to survive the development process. It has been shown that the Young’s modulus of the solid film can 27 be varied over seven orders of magnitude, from that of a viscoelastic material through a rubbery regime 28 to that of a glassy one, by increasing the e-beam dose. At higher doses, excessive backscattering was 29 observed, as well as film swelling, resulting in poor spatial resolution. 3

The use of plasma-polymerised fluoropolymer (CFxOy) thin films in the manufacture of microelectromechanical systems (MEMS) devices is well-established, being employed in the passivation step of the deep reactive ion etching (DRIE) process, for example. This paper presents an investigation of the effect of exposure to organic and aqueous liquid media on plasma-polymerised CFxOy thin films. Atomic force microscopy (AFM), scanning electron microscopy (SEM), ellipsometry, X-ray photoelectron spectroscopy (XPS) and dynamic wetting measurements were all employed as characterisation techniques. Highly basic aqueous solutions, including known silicon etchants, were found to cause delamination via degradation of the countersurface below the CFxOy thin film. Films were found to be stable in organic solvents, acidic aqueous solutions and slightly basic aqueous solutions. 2011 Published by Elsevier Ltd.

We have developed a range of fullerene containing materials for use as organic hard masks. Recent advances in material development are reported together with some results from external evaluations of the original HM100 series. Initial results for the new HM340-383-010 formulation show it to have a high thermal stability (~5.5 % mass loss at 400°C) and a very high carbon content (at 95.3%), offering high etch durability.

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Patterned mineralisation is a feature of many hard-tissues. The impressive mechanical properties exhibited by such tissues can be, in part, attributed to the patterned deposition of mineral within the organic matrix. Although not thermodynamically favourable, the deposition of calcium phosphate based mineral within collagen fibres occurs in vivo in bone and dentine. As a consequence, numerous researchers have investigated how matrix proteins may be conditioned to enable patterned mineral deposition to recapitulate the structures found in nature. In this study, we have demonstrated that this patterned mineralisation of collagen type I may be induced simply by the pretreatment of the collagen with orthosilicic acid (OSA). The OSA treatment of the collagen resulted in a structural change to the collagen fibres, modifying the fibril diameter and changing the kinetics of fibre formation. NMR demonstrated that the OSA was preferentially located at the termini of the procollagen fibrils, thereby templating the formation of apatitic calcium phosphate crystals within the collagen fibrils (as shown using TEM, EDX and SAED). This work demonstrates how simple inorganic ions can have potent effects on structuring biological precipitates and suggests why trace quantities of silicon ions are essential to the formation of healthy hard tissues.

22 Objectives The adhesion of colloidal probes of stainless steel, glass and cellulose to 23 Pseudomonas fluorescens biofilms was examined using atomic force microscopy (AFM) 24 to allow comparisons between surfaces to which biofilms might adhere. 25 Results Biofilm was grown on a stainless steel substrate, and covered most of the surface 26 after 96 h. AFM approach and retraction curves were obtained when the biofilm was 27 immersed in a tryptone soy medium. On approach, all the colloidal probes experienced a 28 long non-contact phase more than 100 nm in length, possibly due to the steric repulsion 29 by extracellular polymers from the biofilm and hydrophobic effects. Retraction data 30 showed that the adhesion varied from position to position on the biofilm. The mean value 31 of adhesion of glass to the biofilm (48 ± 7 nN ) was the greatest, followed by stainless 32 steel (30 ± 7 nN) and cellulose (7.8 ± 0.4 nN). 33 Conclusion The method allows understanding of adheison between the three materials 34 and biofilm, and development of a better strategy to remove the biofilm from these 35 surfaces relevant to different industrial applications. 36

The fabrication of structured polymer/nanoparticle composite films through a combination of additive, subtractive and self-assembly methodologies is investigated. Consumer grade inkjet printing hardware is employed to deposit cationic polyelectrolytes on (i) hydrophilic and (ii) hydrophobised glass substrates. The hydrophobisation process controls the spreading of the droplets and hence the lateral size of printed features. The printed cationic polyelectrolyte regions are used as a template to direct the self-assembly of negatively charged gold nanoparticles onto the surface. Micro-scale features are created in the polyelectrolyte/nanoparticle films using AFM scratching to selectively displace material. The effect of substrate wettability on film morphology is discussed.

In this work typical mechanical properties for a catalyst support material, ZSM5 (a spray-dried granular zeolite), have been measured in order to relate the bulk behaviour of the powder material to the single particle mechanical properties. Particle shape and size distribution of the powders, determined by laser diffraction and scanning electron microscopy (SEM), confirmed the spherical shape of the spray-dried particles. The excellent flowability of the material was assessed by typical methods such as the Hausner ratio and the Carr index. This was confirmed by bulk measurements of the particle-particle internal friction parameter and flow function using a Schulze shear cell, which also illustrated the low compressibility of the material. Single particle compression was used to characterize single particle mechanical properties such as reduced elastic modulus and strength from Hertz contact mechanics theory. Comparison with surface properties obtained from nanoindentation suggests heterogeneity, the surface being harder than the core. In order to evaluate the relationship between single particle mechanical properties and bulk compression behaviour, uniaxial confined compression was carried out. It was determined that the Adams model was suitable for describing the bulk compression and furthermore that the Adams model parameter, apparent strength of single particles, was in good agreement with the single particle strength determined from single particle compression test. (C) 2013 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

In this study, the effects of dwell time on Ga^+ focused ion beam machining at 30keV for different milling currents were investigated. The surface topographies were analysed using atomic force microscopy (AFM) and the substrate structures were investigated by means of Raman spectroscopy. It has been observed that by increasing dwell time the total sputtering yield was increased even though the total dose was remained the same. Also the silicon damage by ion bombardment is reduced as the dwell time is increased. This is mainly due to catalyst behaviour of Ga inside Si which over a period of hours causes recrystallization of Si at room temperature by lowering the activation energy for crystallization.