Controlled fabrication and system integration of CNT-based ionic actuators - example: Liquid handling for biomedical applications: Poster presented at EuroEAP 2016, International Conference on Electromechanically Active Polymer (EAP) Transducers & Artificial Muscles, 14-15 June 2016, Helsingør, Denmark

CNT-based ionic EAPs present a unique and promising actuator material for a variety of potential applications, because they offer a safe way of transforming low-voltage electrical energy into mechanical work. However, due to rather complex manufacturing techniques and low electromechanical efficiencies only very few applications for CNT actuators have been in the focus of R&D activities. Multiple variations of materials, dispersing methods and assembly processes have been adopted throughout the years with the aim to optimize not only performance (stress, strain and reaction rate), but also reproducibility of actuators. Current state of the art production methods are still in the domain of lab scale. The growing interest from multiple industry sectors has now created the need for the scientific community to come together and develop new or adapt existing manufacturing routes capable of mass production for the expected demand of the future. A focus on biomedical applications, fabrication control and system integration of the actuators to enable increased reproducible performance will be the aim of this work. We explore topics from additive manufacturing technology enabling ease of system integration to the influence of electronic contacts on the reproducibility of actuator performance

Improving the manufacturing speed and the reproducibility of ionic CNT actuators by the use of screen printed electrodes: Poster presented at EuroEAP 2016, International Conference on Electromechanically Active Polymer (EAP) Transducers & Artificial Muscles, 14-15 June 2016, Helsingør, Denmark

Electroactive polymer (EAP) actuators based on carbon nanotubes (CNTs) have found great interest in research and have the potential to be used in the field of soft robotics. They provide many advantages such as a low driving voltage, a noiseless movement and are lightweight. However, up to now ionic CNT actuators are not ready to be integrated into products that are ready-to-market. This is due to their moderate performance and their low reproducibility. In this poster the focus is on the reproducibility and the manufacturing speed of screen printed ionic CNT EAP actuators. The manufacturing of solution processed actuators can be divided into two steps. Firstly, the dispersion for the separator and the electrodes has to be made. Secondly, these materials have to be processed with different coating technologies. Commonly the dispersion is made by the use of a magnetic stirrer which in general is a slow dispersing method. In contrast an ultrasonic horn is used to reduce the time that is required to make the dispersion for the electrodes. Casting into a mould is mostly used to make the separation layers and the electrodes. With this technique thick layers can be realized, again however, solidification using this method is time consuming due to the large amount of solvent which has to evaporate. To reduce the manufacturing time of actuators and to improve the reproducibility, screen printing is used to print the electrodes of ionic CNT EAP actuators

Bowel health, defecation patterns and nutrient intake following adoption of a vegan diet: a randomized-controlled trial

The beneficial effects of a plant-based diet on gut microbiota diversity are well documented, however, its impact on clinical bowel health and defecation patterns are less well understood. Vegetarian diets have been associated with a higher bowel movement (BM) frequency as well as softer stools in cross-sectional studies. The effects of the de-novo adoption of a vegan diet on bowel health, however, have never been investigated in a randomized-controlled trial. The present study examined bowel health and defecation patterns in relation to diet and nutrient intake in a young and healthy sample of n = 65 physically-active German university students who were randomly assigned to either a vegan or a meat-rich diet for eight weeks. Bowel health assessment included the Bristol Stool Form Scale (BSFS), the Gastrointestinal Quality of Life Index (GIQLI) and the Cleveland Clinic Fecal Incontinence Score (CCFIS). Nutrient intake was assessed using weighed food diaries. The study was prospectively registered at the German Clinical Trial Register (DRKS00031541). Weekly BM frequency slightly increased in vegans, whereas it remained unaltered in participants assigned to a meat-rich diet. Fiber intake increased significantly in vegans (34.89 (18.46) g/d) whereas it decreased in those assigned to the meat-rich group (22.79 (12.5) g/d). No significant intergroup differences in BSFS and CCFIS patterns were observed. Adoption of a vegan diet neither resulted in a transient increase in abdominal discomfort nor in a decreased gastrointestinal quality of life, which was comparable across the diet groups. The short-term de-novo adoption of a vegan diet did not negatively affect markers of bowel health in this study.</p