Sort by
100 m min<sup>−1</sup> Industrial‐Scale Flexographic Printing of Graphene‐Incorporated Conductive Ink

Flexographic printing is promising for large‐area electronics due to high print‐speed and roll‐to‐roll capability. There have been recent attempts in using graphene as an active pigment in inks, most notably for slower techniques such as inkjet and screen printing. However, formulation of graphene‐enhanced inks for high‐speed printing and its effect on key metrics have never been investigated. Herein, graphene nanoplatelets (GPs) are incorporated to a conductive flexographic ink without compromising the rheological properties. An industrial scale at 100 m min−1 is printed on paper and polyethylene terephthalate (PET) substrates using a commercial flexographic press, and statistical performance variations are investigated across entire print runs. It is shown that GP‐incorporation improves sheet‐resistance (Rs) and uniformity, with up to 54% improvement in average Rs and 45% improvement in the standard‐deviation on PET. The adhesion on both the substrates improves with GP‐incorporation, as verified by tape/crosshatch tests. The durability of GP‐enhanced samples is probed with a 1000 cyclic bend‐test, with 0.31% average variation in resistance in the flat state on PET between the first and last 100 bends, exhibiting a robust print. The statistically scalable results show that GP‐incorporation offers a cost‐performance advantage for flexographic printing of large‐area conductive patterns without modifications to traditional high‐speed graphics printing presses.

Open Access
Relevant
Conformal Printing of Graphene for Single‐ and Multilayered Devices onto Arbitrarily Shaped 3D Surfaces

AbstractPrinting has drawn a lot of attention as a means of low per‐unit cost and high throughput patterning of graphene inks for scaled‐up thin‐form factor device manufacturing. However, traditional printing processes require a flat surface and are incapable of achieving patterning onto 3D objects. Here, a conformal printing method is presented to achieve functional graphene‐based patterns onto arbitrarily shaped surfaces. Using experimental design, a water‐insoluble graphene ink with optimum conductivity is formulated. Then single‐ and multilayered electrically functional structures are printed onto a sacrificial layer using conventional screen printing. The print is then floated on water, allowing the dissolution of the sacrificial layer, while retaining the functional patterns. The single‐ and multilayer patterns can then be directly transferred onto arbitrarily shaped 3D objects without requiring any postdeposition processing. Using this technique, conformal printing of single‐ and multilayer functional devices that include joule heaters, resistive deformation sensors, and proximity sensors on hard, flexible, and soft substrates, such as glass, latex, thermoplastics, textiles, and even candies and marshmallows, is demonstrated. This simple strategy promises to add new device and sensing functionalities to previously inert 3D surfaces.

Open Access
Relevant
Preparing to observe the impact of therapeutic teaching practices. From Flow to self regulation and learning

This paper outlines the research process that aimed to evidence the impact of therapeutic teaching practice within a school for young people with social and emotional challenges resulting from adverse childhood experiences. It is an issue for society that many children and young people have traumatic experiences in their lives that seriously impact on their wellbeing, health and capacities to learn. This paper outlines a New Approach to supporting such vulnerable learners. The project entitled «Learning in a new key» (LINK) involved music therapists working with non-music specialist teachers to introduce musical listening and improvisation as a regular group therapeutic experience in the classroom. The music of our society is a deep cultural reservoir that can be drawn on by teachers to soothe, nurture and potentially heal our troubled and vulnerable young people. The observational schedule herein described was developed during the second year of the project to measure the impact of this work on individual young people. The tool originated from the work of Csikszentmihalyi (1990), to assess the optimal state of being, he called Flow. The concept was developed further to enable researchers to observe and measure the Flow experience in classrooms with young children engaged in active music making (Addessi, Ferrari, & Carugati, 2015). This paper maps the growth of the observation tool within the LINK Project drawing on ideas from early years education, therapeutic practice and psychology. Research into the impact of music listening and making on brain development and healing has also influenced the design of the schedule leading to insights about sensory processing and relationality (Perry & Hambrick, 2008). The use of Flow variables is a relatively new approach in education where systems would benefit from being able to develop a rationale for such practice to meet the challenging needs of children and young people with adverse childhood experiences. Discussion of the potential for the Flow observation schedule will be explored and recommendations for the future identified that will include the use by individual teachers.

Relevant