Biomimetics and Biomimicry in Engineering

Posts Tagged ‘Publications’

Mathematical modelling of sonicated bubbles

In Publications on 2017/05/31 at 5:10 pm

One possible manufacturing method for bone scaffolds used in regenerative medicine involves the acoustic irradiation of a reacting polymer foam to generate a graded porosity. Sonication of foams have been our focus of research for many years now as this technology allows the porosity tailoring of cellular materials.

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Sonicated foam (energy received from the left) with a marked gradation in porosity

We have joined forces with Prof Mulholland’s team (Dr Barlow and Dr Bradley) at Strathclyde University and worked on a mathematical model of a non-reacting process in order to develop theoretical confirmation of the influence of the acoustic signal on the polymer foam.

The model describes single bubble growth in a free rising, nonreacting polymer foam irradiated by an acoustic standing wave and incorporates the effects of inertia. Investigations are carried out to explore the influence of inertia on the bubble volume, fluid pressure and the stress tensors of the foam, and to explore the effect of fluid viscosity and acoustic pressure amplitude on the final bubble volume, and the curing time. A key result is that increasing the applied acoustic pressure is shown to result in a reduced steady state bubble volume, indicating that ultrasonic irradiation has the potential to produce tailored porosity profiles in cellular materials such as bioengineering scaffolds and light-weight structures.

Our work has been compiled as a paper recently published in the Journal of Non-Newtonian Fluid Mechanics and can be found here (Open Access).

Applying International Standards to manage comfort

In Publications on 2017/03/01 at 6:46 pm

Have you ever seen the seat testing device at IKEA? We have used a very similar one in our study.

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IKEA durability test

Open cell polymeric foams can be tailored so that the support provided and the level of stability is customised to people’s needs. For those who are bed bound or wheelchair users the selection of a cushion can improve their health and general well being. Avoiding pressure points, managing sores and permitting air permeability are the three main design specifications that patients and clinicians aim to when choosing a cushion. In addition to that, a functional cushion, such as those who support lateral movements (e.g. leaning sideways to grab a glass of water and be helped to return to your initial position without compromising one’s stability) and protect from vibration and impacts (e.g. dropping off a curb), are the focus of our last research project.

My team and I have had the privilege to work with the biomechanics and physiotherapists at the SMART Centre at Astley Ainslie Hospital in Edinburgh to study how we can help their clinician colleagues understand cushion performance and therefore aid them with the prescription of these to patients and users.

The results from our study have been presented at the PMG 2012 Conference and recently published by the Assistive Technology journal (free e-prints can be collected here). This has allowed us to interact with the community that is preparing the new version of the ISO16840-2:2007 which will regulate developments in this area.

 

Empowering resilient communities

In Publications on 2017/02/06 at 10:58 pm

We have created low-cost housing solutions for the local community in Pabal (India). Those people have a lot of ingenuity but not a lot of money to buy expensive building materials. Only the transport to their villages would cost them a significant amount.

But they have a wealth of natural resources. And amongst them, they have bamboo, a fascinating multifunctional material, ideal for structure-erecting, wind-loading and vibration-proofing due to its heterogeneous porous structure and high shear modulus.

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Bamboo: macro and microstructure

We have helped them to build those modular huts by providing them with a set of instructions that are universal and accessible to all, no matter the mother tongue, ability or building skills. In this way they are prepared to adapt and be resilient to the threats posed by natural forces and climate change hazards (e.g. floods, pluvial, wind, earth tremors) and reinforce their coping strategy as a resilient community.

In the process of developing those instructions we have learnt a lot from the Information Design community. There is so much lo learn about user-centric design, cognitive load and the language of actions, perspectives and colours to convey instructions and allow self-guidance. I deeply thank them for having mentored us.

Our work can be read here and directly on the Information Design Journal site

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Information Design Journal 2016 volume 22 no. 1

 

Making sense of standardisation

In Publications on 2013/11/18 at 12:27 am

Standardisation is that useful process that allows us engineers to share a common ‘plane of reference’ on which to base our conversations. It is useful to know that a material (say, a slab of titanium) has the same mechanical properties when it is measured in Loughborough, Sydney, Lima or Granada.

But sometimes standardisation goes too far on the other extreme. The over-translation from observation to technical definitions might turn an ISO norm into a document that is no longer useful for practical purposes. This is particularly risky when ISO norms attempt to tabulate and measure in ‘softer’ areas such as healthcare and rehabilitation.

In a piece of work recently published here, my colleagues from the NHS Scotland SMART Centre and we have restated some practical insight to an ISO norm that guides the characterisation of wheelchair cushions for a better guidance to prescription by clinicians.

Our work has been well received by the practising community and we look forward to continue working with them.

Ref: Hollington J., Hillman S.J., Torres-Sanchez C., Boeckx J., Crossan N., “ISO 16840-2:2007 load deflection and hysteresis measurements for a sample of wheelchair seating cushions”, Medical Engineering & Physics, in press. DOI:10.1016/j.medengphy.2013.10.010 

Best Free Paper for our work on Prosthetic Devices

In Knowledge Transfer, Publications, Seminars and Keynotes on 2012/04/23 at 11:47 am

Our collaborators Susan Hillman and James Hollington, from the SMART Centre, NHS Scotland, have been awarded Best Free Paper for our  ‘Clinical Interpretation of ISO 16840-2, Measurements for Wheelchair Seating Cushions’ presentation at the Posture and Mobility Group (PMG) National Training Event.

Their stand also attracted a lot of interest from clinicians, manufacturers and the ISO and BSI committees.

James at the stand with clinicians

This collaborative project is focused on checking the clinical relevance of the BS ISO standard 1640-2:2007 on Wheelchair seating for the determination of physical and mechanical characteristics of devices intended to manage tissue integrity, in this case, wheelchair seat cushions. Our paper can be read here: PMG 2012.

Susan and James discussing our work with colleagues

Congratulations Susan and James!

(More info about the centre)

Crowdsourcing publications

In Publications on 2010/04/02 at 4:49 pm

The team has been busy in the last few weeks and our efforts have crystallized into Journal and Conference papers.

“Putting the crowd to work in the knowledge-based factory” has been accepted for publication in to the Advanced Engineering Informatics Journal, special issue on the Cognitive Factory; and  “Outsourcing labour to the Cloud” is accepted for publication in the general issue of the International Journal of Innovation and Sustainable Development.

Paola DiMaio will present in Dubai our paper on Library Searches, a joint project with the National Library of Scotland: “Towards Crowdsourcing translation tasks in library cataloguing”, IEEE International Conference on Digital Ecosystems and Technology (DEST), Special Track on  “Web Based Harnessing of Human Collective Intelligence”, 12-15 April 2010, Dubai, United Arab Emirates.

Check the ‘Publications’ section for full details on these and other publications