Active chainmail fabrics for soft robotic applications

This paper introduces a novel type of smart textile with electronically responsive flexibility. The chainmail inspired fabric is modelled parametrically and simulated via a rigid body physics framework with an embedded model of temperature controlled actuation. Our model assumes that individual fabric linkages are rigid and deform only through their own actuation, thereby decoupling flexibility from stiffness. A physical prototype of the active fabric is constructed and it is shown that flexibility can be significantly controlled through actuator strains of ≤10%. Applications of these materials to soft-robotics such as dynamically reconfigurable orthoses and splints are discussed

The ultimate wearable: Connecting prosthetic limbs to the IoPH

A new wearable device called the 'Ubi-Sleeve' is currently being developed that enables prosthesis wearers and other stakeholders to review temperature, humidity and prosthesis slippage behavior during everyday prosthesis wear. A combination of custom 3D printed strain sensors and off the shelf temperature and humidity sensors will be integrated into an unobtrusive sleeve to create a device that enables a deeper level of understanding of heat and sweat issues. To create the device, a series of experiments are in progress that will quantify changes in heat, humidity and slippage that negatively affect the prosthesis experience. Interviews and focus groups are also being conducted to gain a deeper understanding of the human side of prosthesis wear and to also ensure that data are presented in a way that is effective, useful and easy to understand

An AI-Based Model for Texture Classification from Vibrational Feedback: Towards Development of Self-Adapting Sensory Robotic Prosthesis

This paper presents a novel method of tuning vibration parameters to elicit specific perceptions of texture using vibration artefacts detected in EMG signals. Though often used for prosthetic control, sensory feedback modalities like vibration can be used to convey proprioceptive or sensory information. Literature has shown that the presence of sensory feedback in prosthesis can improve embodiment and control of prosthetic devices. However, it is not widely adopted in daily prosthesis use, due in large part to the daily change in perception and interpretation of the sensory modality. This results in daily parameter adjustments so that sensory perception can be maintained over time. A method therefore needs to be established to maintain perception generated by modalities like vibrations. This paper investigates modulating the vibration parameters based on how the vibrations dissipate in the surrounding tissue from the stimuli. This is with the aim of correlating dissipation of vibration to specific perceptions of texture. Participants were asked to control vibration motor parameters to elicit the perception of three different grades of sandpaper, provided to them for reference. Once the vibration parameters were chosen a CNN algorithm identified and categorized the artefact features along equidistantly spaced EMG electrodes. Participants were asked to repeat this experiment on three separate days and on the fourth was asked to complete a texture identification task. The task involved identifying the texture of the sandpaper based on their previously chosen parameters and compared the results to tuning against an AI-based algorithm using the dissipation of the vibration artefacts

Influences on single-use and reusable cup use: a multidisciplinary mixed-methods approach to designing interventions reducing plastic waste

An estimated 2.5–5 billion single-use coffee cups are disposed of annually in the UK, most of which consist of paper with a plastic lining. Due to the difficulty of recycling poly-coated material, most of these cups end up incinerated or put in landfills. As drinking (take-away) hot beverages is a behaviour, behaviour change interventions are necessary to reduce the environmental impacts of single-use coffee cup waste. Basing the design of interventions on a theoretical understanding of behaviour increases the transparency of the development process, the likelihood that the desired changes in behaviour will occur and the potential to synthesise findings across studies. The present paper presents a methodology for identifying influences on using single-use and reusable cups as a basis for designing intervention strategies. Two behaviour change frameworks: The Theoretical Domains Framework (TDF) and the Capability-Opportunity-Motivation-Behaviour (COMB) model of behaviour, were used to develop an online survey and follow-up interviews. Research findings can inform the selection of intervention strategies using a third framework, the Behaviour Change Wheel (BCW). The application of the methodology is illustrated in relation to understanding barriers and enablers to single-use and reusable cup use across the setting of a London university campus. We have developed a detailed method for identifying behavioural influences relevant to pro-environmental behaviours, together with practical guidance for each step and a worked example. Benefits of this work include it providing guidance on developing study materials and collecting and analysing data. We offer this methodology to the intervention development and implementation community to assist in the application of behaviour change theory to interventions

Truss model for stress controlled morphogenesis

We resort to the usual decomposition of the deformation gradient into an active and a passive component, and deduce the constitutive law and equilibrium equations when the two components are not independent. In the model described here the active of the deformation is related to the hyperelastic passive part through a control function that simulates a feedback mechanism that has been experimentally observed during embryo development. Using a variational approach, we first write the equations for continua and study the effects of the control function in these equations. We particularise the results for a system of trusses, which allows us to obtain a simplified set of equations. In our derivations, we apply special attention to the conditions that a thermodynamically complaint formulation should satisfy. We particularise these equations and conditions for the relevant elements of the cytoskeleton, namely, microfilaments and microtubules. We apply the model to simulate the shape changes observed during invagination of the Drosophila Melanogaster embryo. As a salient result, the model reveals that the incompressibility constraint of the yolk furnishes a necessary pressure on the epithelium that eventually eases its internalisation.Postprint (published version

Barriers and Enablers to Buying Biodegradable and Compostable Plastic Packaging

Biodegradable and compostable plastic packaging (BCPP) has the potential to reduce a global plastic waste problem. We aimed to identify influences on buying BCPP as a basis for designing strategies that enable BCPP’s environmental benefits. Using a UK-focused citizen science dataset, we thematically analysed 610 survey responses to a question exploring reasons for BCPP purchase. Themes are categorised as barriers and enablers and according to the components of the Capability, Opportunity, Motivation, and Behaviour (COM-B) model of behaviour. Key barriers concerned: psychological capability (not understanding terminology used to label packaging, not taking notice of packaging, and preferring other types of packaging and product qualities); reflective motivation (negative beliefs about BCPP’s environmental impacts and skepticism over decomposition claims), and physical opportunity (no access to appropriate waste management). Key enablers concern: reflective motivation (positive beliefs about BCPP’s environmental impact and resolve to behave pro-environmentally) and physical opportunity (access to appropriate waste management). Reducing ambiguity concerning the labels of biodegradable and compostable may reduce skepticism over environmental claims of packaging. Interventions should improve information about the source of the packaging material, how the packaging waste is processed, and how to dispose of the packaging. This will not be sufficient unless facilities for local BCPP waste collection and processing are increased

Barriers and Enablers to Food Waste Recycling: A Mixed Methods Study amongst UK Citizens

We aim to identify influences on UK citizens’ household food waste recycling as a basis for designing strategies to increase household food waste collection rates via local services. Using a UK dataset (n = 1801) and the COM-B (Capability–Opportunity–Motivation–Behaviour) model as a theoretical framework, we conduct quantitative regression and supporting thematic analyses to investigate influences on citizens’ recycling of food waste. Results show that automatic motivation (e.g., emotions and habit) and psychological capability (e.g., knowledge) predict household food waste recycling. Physical opportunity (i.e., dealing with food waste in other ways such as homecomposting or feeding pets/strays, time and financial costs) was the main barrier to recycling food waste identified in thematic analyses. Participants also reported automatic motivation-related barriers such as concerns over pests, odour, hygiene and local authorities’ food waste collection capabilities. Based on findings we recommend the development of clear, consistent communications aimed at creating positive social norms relating to recycling and increasing knowledge of what can and cannot be put in food waste bins. Improved functional design and free distribution of bins and compostable caddy liners developed according to user-centred needs for cleanliness, convenience and hygiene are also needed. These will not be sufficient without a nationally uniform, efficient and reliable system of household food waste collection

An Investigation into the Dissipation of Vibrations Using Electromyography towards the Development of Self-Adapting Robotic Prosthesis

Vibrations can be used to convey positional or sensory information to prosthetic users. However, for the feedback to convey information consistently, daily fine-grained adjustments are required. This paper investigates whether vibration dissipation through the muscle can be tracked using EMG with the aim of providing reliable, long-term sensory feedback. The results of this study showed that the magnitude of vibration artifacts can be measured using EMG and used to create a dissipation trend. This trend varies between participants but shows consistency for individuals when measured across multiple days. This novel way of measuring vibration dissipation can potentially be used as a basis for adaptive sensory control in future prosthesis studies

The use of phase change material as an actuator in linkage fabric structures

Linkage fabric structures show potential as assistive technology that can provide support and assistance for individuals with specific mobility and disability needs. The core functionality of these fabrics is the ability to passively and actively control the mechanics of each link producing a structure with variable and adjustable stiffness. Current actuators have shown limited ability to produce active stiffening within a fabric structure without the addition of a continuous energy supply to the structure, therefore, limiting its use as wearable assistive technology. Here, we address the energy supply problem and show the novel use of sodium acetate trihydrate (SAT) in the linkage structures to induce mechanical stiffening through a phase change induced by an electric impulse. We find that a SAT aqueous concentration of 55 wt% is optimum to achieve a stable supercooled liquid (to ambient temperature) and effective electrical nucleation from liquid to solid, which provides robust locking mechanism of individual linkages able to withstand mechanical torsion up to 200 mNm. We demonstrate proof of principle through the integration of SAT into one- and two-dimensional linkage structures and their nearly instantaneous stiffening within each link by enabling electrically controlled actuation