Darshil U Shah

Darshil U Shah
University of Cambridge | Cam · Department of Architecture

BEng (Hons), PhD

About

99
Publications
88,178
Reads
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3,666
Citations
Additional affiliations
January 2019 - present
University of Cambridge
Position
  • Lecturer
October 2018 - January 2019
University of Cambridge
Position
  • Research Associate
January 2015 - October 2018
University of Cambridge
Position
  • PostDoc Position

Publications

Publications (99)
Article
To aid design engineers in closing the existing gap between current scientific knowledge and actual market applications of plant fibre reinforced plastics (PFRPs), this article provides comprehensive Ashby-type materials selection charts for PFRPs to facilitate product design and development. General tensile mechanical property profiles are present...
Article
Full-text available
Plant fibres, perceived as environmentally sustainable substitutes to E-glass, are increasingly being employed as reinforcements in polymer matrix composites. However, despite the promising technical properties of cellulose-based fibres and the historic use of plant fibre reinforced plastics (PFRPs) in load-bearing components, the industrial uptake...
Article
Full-text available
Here we characterise the thermal properties of engineered bamboo panels produced in Canada, China, and Colombia. Specimens are processed from either Moso or Guadua bamboo into multi-layered panels for use as cladding, flooring or walling. We utilise the transient plane source method to measure their thermal properties and confirm a linear relations...
Article
Full-text available
In directly addressing the question, ‘can flax replace E-glass as a reinforcement for structural composites?’, this manuscript adopts a novel comparative case study approach to investigate the manufacture and mechanical testing of full-scale 3.5-m composite rotor blades (suitable for 11 kW turbines) built from flax/polyester and E-glass/polyester.T...
Article
Full-text available
With the growing interest in bio-based composites as alternatives to traditional glass fibre reinforced composites (GFRPs), there has been a persistent rise in the commercial use of plant fibre composites (PFRPs). In contrast, nature’s ‘wonder-fibre’ silk has had no commercial applications, and only limited scientific investigations, as a composite...
Article
Full-text available
Insight into fibre formation can provide new rationale for the design and preparation of fibres with programmed mechanical properties. While synthetic bioinspired fibres have shown impressive tensile properties, the fibre formation process remains poorly understood. Moreover, these systems are highly complex and their formation is environmentally a...
Article
Flax fibres are widely used in the automotive sector to reinforce polyolefins, such as for dashboard and interior door panels. A promising option is poly-(lactid) (PLA), as it leads to higher mechanical properties and offers an additional end-of-life scenario following recycling: industrial composting. However, like other composite systems such as...
Article
Full-text available
Due to changing demographics, the UK faces a significant shortage of school places. The UK government aims to build large numbers of new schools to meet this demand. However, legally binding carbon emissions mitigation commitments might limit the ability of the government to adequately meet this demand on-time, on-budget, and within sustainability...
Preprint
Full-text available
This research aims to evaluate a realistic timber adoption scenario as a way of reducing carbon emissions of construction in Chile and the UK for the period 2020-2050. The study finds that a gradual increase of timber construction could complement the emission reduction targets set by traditional materials, providing the needed carbon storage. This...
Preprint
Full-text available
The Centre for Natural Material Innovation in the Department of Architecture at the University of Cambridge is a cross-disciplinary centre, bringing together people and research in plant sciences, biochemistry, chemistry, fluid dynamics, engineering, and architecture. Through innovative research and experimentation, we aim to transform the way we b...
Preprint
Full-text available
This working paper is an evidence submitted to the Royal Institution for British Architects that makes the case that the built environment must drastically reduce its carbon emissions to work towards net zero. Here we advocate for climate repair through the built environment by decarbonising UK’s building sector through both improved energy efficie...
Preprint
Full-text available
This research aims to evaluate a realistic timber adoption scenario as a way of reducing carbon emissions of construction in Chile and the UK for the period 2020-2050. The study finds that a gradual increase of timber construction could complement the emission reduction targets set by traditional materials, providing the needed carbon storage. This...
Article
Flax/Poly-(lactide) non-woven composites are an alternative to conventional glass/poly-(propylene), offering a potentially lower environmental impact solution for the automotive industry. To understand this complex material, its detailed architecture and void distribution are examined through 3D microtomography. Anisotropy in fibre orientation is a...
Article
Full-text available
Flax has a long and fascinating history. This plant was domesticated around 8,000 bce1 in the Fertile Crescent area2, first for its seeds and then for its fibres1,3. Although its uses existed long before domestication, residues of flax yarn dated 30,000 years ago have been found in the Caucasus area4. However, Ancient Egypt laid the foundations for...
Conference Paper
Full-text available
The optimum welding time for welded beech specimens is assessed with a compression shear test method and the softening of the wood polymers during friction welding is evaluated by dynamic mechanical analysis (DMA). A welding time of 2-3 sec yields the highest mechanical performance (13.6-14.7 MPa) that is equivalent to the shear strength of glued-l...
Article
Natural rubber foam (NRF) products are frequently required in high resilience or high shape recoverability applications, which is in contrast to the fundamental nature of NRF. This study aims to improve NRF properties, such as recovery, by increasing the amount of vulcanizing chemicals (Vc) and adding cassava starch (Cs). Interestingly, increasing...
Article
Full-text available
Wood presents a hierarchical structure, containing features at all length scales: from the tracheids or vessels that make up its cellular structure, through to the microfibrils within the cell walls, down to the molecular architecture of the cellulose, lignin, and hemicelluloses that comprise its chemical makeup. This structure renders it with high...
Article
Full-text available
PLA-flax non-woven composites are promising materials, coupling high performance and possible degradation at their end of life. To explore their ageing mechanisms during garden com-posting, microstructural investigations were carried out through scanning electron microscopy (SEM) and atomic force microscopy (AFM). We observe that flax fibres prefer...
Article
Full-text available
Willow has been used for nearly 200 years as the main material in the blades of cricket bats, whilst the application of bamboo in sport has declined. In this work, laminated bamboo was characterised to assess if it could be a viable alternative to willow. Bamboo matures much more quickly than willow and is prevalent in countries, such as India, whe...
Article
Retting of fibrous plants such as flax is an essential step in the extraction of fibre bundles and their transformation into textiles and reinforcement fabrics for use in garments and composites. Dew-retting is traditionally performed from Northwest France to the Netherlands, as the climate is highly favourable for this process. Hemp is a plant tha...
Article
Full-text available
The COVID-19 pandemic has created enormous global demand for personal protective equipment (PPE). Face shields are an important component of PPE for front-line workers in the context of the COVID-19 pandemic, providing protection of the face from splashes and sprays of virus-containing fluids. Existing face shield designs and manufacturing procedur...
Article
Full-text available
Wider use of timber has the potential to greatly reduce the embodied carbon of construction. Improved chemical treatment could help overcome some of the barriers to wider application of timber, by furthering the durability and/or mechanical properties of this natural material. Improving timber treatment by treating the whole volume of a piece of ti...
Preprint
Full-text available
Manufacturing natural based high-performance composites is becoming a greater interest to the composite manufacturers and to their end users due to their bio-degredability,low cost and availability. Yarn based textile architecture is commonly used in manufacturing these composites due to their excellent formability. However, for using natural based...
Article
The use of laminated bamboo in structural applications is increasing, but the failure mechanisms of the material need further investigation. This study investigated the failure of laminated bamboo under compressive loading using digital image correlation (DIC). Notably, the unique speckled appearance of a bamboo transverse section, resulting from t...
Article
Full-text available
Replacing glass fibres with flax fibres is a first step in reducing the ecological impact of thermoset composite materials, and employing a biodegradable thermoplastic matrix opens up recycling and composting as end-of-life routes. Here, a range of flax fibre reinforced biodegradable thermoplastics were investigated: poly-(hydroxy alkanoate) (PHA),...
Article
Silk spinning has evolved many times in nature enabling a variety of organisms to produce fibers boasting exceptional properties, notably high strength, and toughness, through energy- and resource-efficient processes. This has motivated scientists to both understand natural silk spinning processes, and replicate such processes or create new process...
Article
Full-text available
Three thermoset resin systems—bio-epoxy, epoxy, and polyester-with 30 v% flax fiber reinforcement have been studied to identify the optimal fiber–resin combination in a typical composite structure. Tensile, interface and interlaminar shear strength together with flexural and impact damage tolerance were compared in this study. The results revealed...
Article
Full-text available
Liquid composite moulding (LCM) of plant fibre composites has gained much attention for the development of structural biobased composites. To produce quality composites, better understanding of the resin impregnation process and flow behaviour in plant fibre reinforcements is vital. By reviewing the literature, we aim to identify key plant fibre re...
Article
Over the past decades, the use of plant fibre reinforced composites has increased significantly due to their many attractive attributes such as high specific strength and modulus, wide availability, low cost and high environmental credibility compared to their synthetic counterparts. These attributes are especially attractive for lightweight applic...
Article
Full-text available
Polymer foams are an important class of engineering material that are finding diverse applications, including as structural parts in automotive industry, insulation in construction, core materials for sandwich composites, and cushioning in mattresses. The vast majority of these manufactured foams are homogeneous with respect to porosity and structu...
Article
Full-text available
Given the vast amount of available research in the area of natural fibre composites, a significant step forward in the development of next-generation plant fibre-based products would be to devise a framework for rational design. The authors use a top-down approach, starting with an example final product to define the product specifications for high...
Article
Flax shives (FS) represent approximately 50 % in weight of dry flax stems, making it the main by-product of the flax scutching industry. Being an available and low-added value lignocellulosic resource, flax shives are an interesting candidate for thermoplastic composite reinforcement. In this study, raw flax shives were fragmented by knife milling...
Article
Non-woven composites reinforced with plant fibers are widely used in the automotive and construction sectors. The vast majority is composed of petroleum-based, non-compostable polyolefins, which are no longer a viable solution in an environmental context where the end-of-life management of industrial products is becoming a major societal issue. Her...
Article
Semi-consolidated thermoplastic tapes were produced by spreading flax and polypropylene matrix fibres using a newly developed technology. This lightweight tape was structurally stable and contained 38% flax fibres by volume. The tapes were processed in unidirectional and woven fabric format for composite fabrication. We found that the flax/PP tape-...
Article
Full-text available
Timber is the only widely used construction material we can grow. The wood from which it comes has evolved to provide structural support for the tree and to act as a conduit for fluid flow. These flow paths are crucial for engineers to exploit the full potential of timber, by allowing impregnation with liquids that modify the properties or resilien...
Article
Full-text available
Scanning thermal microscopy is a powerful tool for investigating biological materials and structures like bamboo and its cell walls. Alongside nanoscale topographical information, the technique reveals local variations in thermal conductivity of this elegant natural material. We observe that at the tissue scale, fibre cells in the scattered vascula...
Article
In recent years, lignocellulosic biomass has been increasingly used in various applications. While for many of them the plant materials require coarse milling, some new applications for green chemistry, bio-energy and bio-packaging necessitate comminution to obtain very finely calibrated particles (below 200 μm in size). This milling step is not in...
Article
Currently, only two forms of laminated bamboo are commercially available as structural materials: unidirectional beams and boards, and cross-laminated boards. As a natural quasi-unidirectional composite, the lamination of bamboo into plies with specific orientations would allow the design and manufacture of a family of multi-axial composite laminat...
Article
Full-text available
In this study, a gradually increased hydro-mechanical treatments duration were applied to native hemp bast fibres with a traditional pulp and paper beating device (laboratory Valley beater). There is often a trade-off between the treatment applied to the fibres and the effect on their integrity. The multimodal analysis provided an understanding of...
Article
Full-text available
Fully biodegradable flax/polylactic acid (PLA) thermoplastic composites were fabricated by using random (nonwoven mat) and aligned (unidirectional yarn) flax fiber as reinforcements (39% flax by volume) and Polylactic acid (PLA) as matrix. Results revealed that the aligned flax fibers have a greater reinforcing effect due to the uniform distributio...
Article
Date palm fibres are one of the most available natural fibres in North Africa and the Middle East. A significant amount of date palm fibres biomass is wasted annually and only limited amounts are used in low value products. In this study, tensile and low-velocity impact responses of biodegradable, lignocellulosic biomass reinforced polycaprolactone...
Article
Full-text available
Natural materials are a focus for development of low carbon products for a variety of applications. To utilise these materials, processing is required to meet acceptable industry standards. Laminated bamboo is a commercial product that is currently being explored for structural applications, however there is a gap in knowledge about the effects of...
Article
Full-text available
Spider silk is a fascinating material, combining high strength and elasticity that outperforms most synthetic fibers. Another intriguing feature of spider silk is its ability to “supercontract,” shrinking up to 50% when exposed to water. This is likely on account of the entropy‐driven recoiling of secondary structured proteins when water penetrates...
Article
Full-text available
For wood to be used to its full potential as an engineering material, it is necessary to quantify links between its cell geometry and the properties it exhibits at bulk scale. Doing so will make it possible to predict timber properties crucial to engineering, such as mechanical strength and stiffness, and the resistance to fluid flow, and to inform...
Article
Full-text available
Engineered bamboo is being increasingly explored for structural use in the construction sector. To ensure durability, products such as laminated bamboo undergo essential preservation treatment steps during their manufacture. However, the effects of hygro-thermal caramelisation and chemical bleaching, two commonly used treatment procedures in indust...
Article
Full-text available
For the past 15 years, there has been tremendous interest and technological development concerning biocomposites. Plant fibres can be derived from a multitude of natural agro-sources, with the preferred choice as a composite reinforcement often being driven by abundance, geographical location, and historical use. While from a product designer's or...
Article
Full-text available
Laminated bamboo in structural applications has the potential to change the way buildings are constructed. The fibrous microstructure of bamboo can be modelled as a fibre-reinforced composite. This study compares the results of a fibre volume fraction analysis with previous experimental beam bending results. The link between fibre volume fraction a...
Article
Ivory carves well and lasts long even under heavy usage. Its use over millennia are testaments to its value for household items, high-value ornaments and weaponry as well as false teeth and early hip-replacements. Indeed, exceptional toughness is required of the elephant's ivory because its tusk is used by the animal to leverage trees to breaking p...
Chapter
Growing interest in bio-based materials has powered the recent industrial uptake of plant fiber-reinforced plastics. In contrast, nature’s wonder-fiber silk has had no commercial applications and only limited scientific investigations as a composite reinforcement for nonbiomedical applications. In addressing the question “are silks suitable as poly...
Article
2017 This work proposes a multi-scale study of the properties of leaf sheath date palm fibres currently considered as agricultural waste. Firstly, by using optical and electronic microscopy, two main types of bundles were identified which have profoundly different structures. Biochemical analysis and X-ray diffraction (XRD) revealed a low degree of...
Article
Full-text available
Lumen impregnation, unlike most other wood modification methods, is typically assessed by the pore-filling ratio (PFR) (i.e. the fraction of luminal porosity filled) rather than by weight percentage gain (WPG). During lumen impregnation, the impregnants act on the voids in the wood rather than on the solid mass (e.g. cell walls), but the PFR cannot...
Article
This work proposes a multi-scale study of the properties of leaf sheath date palm fibres currently considered as agricultural waste. Firstly, by using optical and electronic microscopy, two main types of bundles were identified which have profoundly different structures. Biochemical analysis and X-ray diffraction (XRD) revealed a low degree of crys...
Article
Laminated bamboo is emerging as a novel material in design and construction. As a natural fibre composite, it has unique mechanical properties that allow for innovations that are not possible in other materials. Here, we discuss one new application of those properties: the development of a novel bending technique using high temperature, and we expl...
Article
Full-text available
From the stems of agricultural crops to the structural trunks of trees, studying the mechanical behaviour of plant stems is critical for both commerce and science. Plant scientists are also increasingly relying on mechanical test data for plant phenotyping. Yet there are neither standardised methods nor systematic reviews of current methods for the...
Article
Full-text available
From the stems of agricultural crops to the structural trunks of trees, studying the mechanical behaviour of plant stems is critical for both commerce and science. Plant scientists are also increasingly relying on mechanical test data for plant phenotyping. Yet there are neither standardised methods nor systematic reviews of current methods for the...
Article
Full-text available
Lumen impregnation, unlike most other wood modification methods, is typically assessed by the pore-filling ratio (PFR) (i.e. the fraction of luminal porosity filled) rather than by weight percentage gain (WPG). During lumen impregnation, the impregnants act on the voids in the wood rather than on the solid mass (e.g. cell walls), but the PFR cannot...
Article
Full-text available
Inspired by biological systems, we report a supramolecular polymer–colloidal hydrogel (SPCH) composed of 98 wt % water that can be readily drawn into uniform ( ∼ ∼6- μ μm thick) “supramolecular fibers” at room temperature. Functionalized polymer-grafted silica nanoparticles, a semicrystalline hydroxyethyl cellulose derivative, and cucurbit[8]uril u...
Article
Full-text available
Laminated bamboo is emerging as a novel material in design and construction. As a natural fibre composite, it has unique mechanical properties that allow for innovations that are not possible in other materials. Here, we discuss one new application of those properties: the development of a novel bending technique using high temperature, and we expl...
Article
Inspired by biological systems, we report a supramolecular polymer-colloidal hydrogel (SPCH) comprising 98 wt% water that can be readily drawn into uniform (ca. 6 µm thick) 'supramolecular fibers' at room temperature. Functionalized polymer-grafted silica nanoparti- cles, a semi-crystalline hydroxyethyl cellulose derivative and cucur- bit[8]uril un...
Article
Jeffrey W. Gilman and co-workers observe interfacial damage in a silk-epoxy-composite in article number 1601018. Hundreds of microns inside a silk-fiber composite, two-photon fluorescence life-time imaging and hyperspectral imaging of a damage-sensing probe (mechanophore), reveals interface debonding, fiber fracture, and chemical reaction with the...