Search Results (45)

Virtual Reality (VR) painting, an emerging form of artistic expression under 5G technology, showcases a broader range of expressive styles and dynamic visual effects compared to traditional computer graphics. The creative process in VR painting enhances spatial depth, exhibiting different spatial abilities and necessitating more physical movements, including hand controllers and foot movements in the virtual space. Furthermore, VR painting in art therapy encourages users to engage in physical activities, contributing to better emotional expression. This study involved digital-native users in VR painting, using Meta Quest 2 to operate Open Brush for their creations. Through observational methods, we examined user operational behaviors and conducted semi-structured interviews post-experiment to explore their painting performance and usage behaviors in the virtual environment. The results of this study indicate that VR painting enhances the sense of space and dynamic expression in creative work and improves users’ emotional and physical engagement, providing new avenues for artistic expression. These findings contribute to improving the usability and application value of VR paintings. Full article

Printed electronics (PEs) are rapidly attracting interest, especially in wearable sensors, smart textiles, and IoT devices. Conductive inks, essential for the fabrication of PE, must be highly conductive, cost-effective, biocompatible, easy to prepare, and less viscous. Conductive inks comprise a conducting material (metals like silver, gold, copper, or carbon-based alternatives like graphite, graphene, and carbon nanotubes), a binder, and a solvent. In this work, a water-based graphite conductive ink is developed using graphite as a conductive material, corn starch powder (non-toxic and biodegradable) as a binder, and distilled water as a solvent. Firstly, corn starch powder is added to distilled water, which is heated up to 100 °C and stirred continuously until a homogeneous gel-like mixture is formed. After cooling the mixture, graphite powder is added to it, and it is stirred for an hour at 450 rpm to obtain the ink. To check the conductivity, the ink is brush-painted on a paper substrate with a dimension of 20 mm × 10 mm and the result shows a low ohmic resistance of ~560 Ω, confirming the highly conductive nature of the ink. Additionally, thermogravimetric analysis (TGA) is performed on the prepared ink to evaluate its thermal stability, and a very strong X-ray diffraction (XRD) peak obtained at 2θ° = 26.5426° and a small peak at 2θ° = 54.6145°, along with a few other small peaks, confirms the presence of graphite with corn starch. Thus, this conductive ink can be used for PEs owing to its affordability, biocompatibility, and ease of preparation. Full article

An important issue in obtaining a good casting surface without defects in contact with the liquid metal is the use of protective coatings on the surface of the moulding sand forming the mould cavity. Protective coatings are based on highly refractory materials that are finely ground and protect the moulding sand from thermal stresses from the molten metal. An important aspect of obtaining the appropriate properties of the protective coatings used is the method of application. This article presents the results of a quality study of the protective coatings obtained, which were applied by dip and painting with a brush. Four different coatings were applied to mould sand samples prepared on grain matrices with different average grain sizes. During the tests, the viscosity of the protective coatings, their gas-forming capacity, sieve analyses of the grain matrix used, the permeability of the moulding sand with the protective coating and the abrasiveness and adhesion of the protective coatings were determined. The quality of the coating obtained was found to depend on its type, the size of the grain matrix used in the moulding sand and the method of application. The experiments carried out indicate that a comparative study of the available protective coatings can indicate the best solution, taking into account the grain matrix used and the method of application adopted. Full article

Recently, there has been a huge increase in the different ways to manufacture polymer-based sensors. Methods like additive manufacturing, microfluidic preparation, and brush painting are just a few examples of new approaches designed to improve sensor features like self-healing, higher sensitivity, reduced drift over time, and lower hysteresis. That being said, we believe there is still a lot of potential to boost the performance of current sensors by applying modeling, classification, and machine learning techniques. With this approach, final sensor users may benefit from inexpensive computational methods instead of dealing with the already mentioned manufacturing routes. In this study, a total of 96 specimens of two commercial brands of Force Sensing Resistors (FSRs) were characterized under the error metrics of drift and hysteresis; the characterization was performed at multiple input voltages in a tailored test bench. It was found that the output voltage at null force (V_{o_null}) of a given specimen is inversely correlated with its drift error, and, consequently, it is possible to predict the sensor’s performance by performing inexpensive electrical measurements on the sensor before deploying it to the final application. Hysteresis error was also studied in regard to V_{o_null} readings; nonetheless, a relationship between V_{o_null} and hysteresis was not found. However, a classification rule base on k-means clustering method was implemented; the clustering allowed us to distinguish in advance between sensors with high and low hysteresis by relying solely on V_{o_null} readings; the method was successfully implemented on Peratech SP200 sensors, but it could be applied to Interlink FSR402 sensors. With the aim of providing a comprehensive insight of the experimental data, the theoretical foundations of FSRs are also presented and correlated with the introduced modeling/classification techniques. Full article

In cultural heritage, paint stratigraphies are complex systems typically consisting of various paint layers with fine crystalline phases mixed with coarse pigment and filler grains. This complexity poses significant challenges for X-ray diffraction (XRD) analysis. In this work, we employed synchrotron radiation micro-X-ray diffraction in transmission geometry (SR-µTXRD) with linear mapping to develop a novel approach for studying the crystalline phases (pigments and fillers) in mock-up paint stratigraphies. A targeted approach was followed for qualitative, quantitative, and microstructural analysis, combining signals from micrometric crystallites and coarse single crystals as well as from randomly oriented and iso-oriented crystalline phases. This allows for identifying, localizing, and quantifying these phases even in low fractions and distinguishes the same phases across different layers with varying grain sizes or spatial orientations. Critical analysis of 2D XRD patterns, coupled with full-profile fitting performed by the Rietveld method, provides insights into material preparation (e.g., grinding), painting technique (e.g., color palette, use of fillers, brushing), and crystallo-chemical modifications over time. This analytical approach, integrating spatially resolved investigation with high-quality phase characterization, enhances the potential of specific XRD methodologies for a 2D investigation of multi-phase materials in cultural heritage, even without dedicated micro-mapping techniques. Full article

This paper presents the methodology developed for underwater measurements using electrochemical impedance spectroscopy (EIS) technique, aimed at determining the resistance of an epoxy coating applied in seawater to the legs of an oil production platform. Performing such underwater tests in an offshore environment was technically challenging. The results of measurements obtained on the platform were confronted with comparative results obtained in the laboratory, where the properties of the coating applied in water collected from the Baltic Sea (thickness, hardness, adhesion, and electrical resistance) were examined. This made it possible to conclude about the correctness of the paint coating application by divers on the legs of the platform. The single-layer epoxy coating applied by brush to the platform legs had a resistance above 10 kΩ∙cm² and thus met the assumed minimum resistance of the protective coating cooperating with cathodic protection as the anti-corrosion protection system of the platform legs. The synergy of these two technologies ensures full protection of offshore structures against corrosion. Measurements of the potential of the platform legs confirmed this. Before painting, the potential value at a depth of 0–15 m was 310 ÷ 320 mV versus the zinc reference electrode, while after painting the potential value decreased to 220 ÷ 240 mV, which means that the effect of full cathodic protection was achieved and the platform legs were protected from corrosion. The developed methodology for underwater EIS measurements on the high seas can be applied to any underwater metal structure to assess the quality of protective coatings. Full article

Robot artistic painting and robot calligraphy do require brush models for brushstroke simulation and painting robot control. One of the main features of the brush is its compliance, which describes the relationship between the brush footprint shape and the pressure applied to the brush. In addition, during motion, the brush footprint position lags from the brush handle position in a complicated manner. To date, the question of creating a physically correct model of these effects and choosing the best method for the model parameter calibration has not been presented in the literature. In the current paper, we derive equations of the brush contact patch motion, give their closed-form solutions, and investigate three methods for the brush model calibration: capturing brush footprints on a matte glass with a camera, painting calibration brushstrokes, and capturing a brush shape side projection with a camera. As we show, calibration brushstrokes give us primary information on brush contact patch displacement during painting, and capturing the brush side projection allows the accurate estimation of the gap from the brush tip to the center of the contact patch. Capturing brush footprints is useful for creating a brushstroke executable model. As an example, a model for a round artistic brush was created and verified in three tests, including measuring the coordinates of an angular brushstroke center line, simulating an angular brushstroke, and writing a signature using a robotic setup. Full article

As one of the precious cultural heritages, Chinese landscape painting has developed unique styles and techniques. Researching the intelligent generation of Chinese landscape paintings from photos can benefit the inheritance of traditional Chinese culture. To address detail loss, blurred outlines, and poor style transfer in present generated results, a model for generating Chinese landscape paintings from photos named Paint-CUT is proposed. In order to solve the problem of detail loss, the SA-ResBlock module is proposed by combining shuffle attention with the resblocks in the generator, which is used to enhance the generator’s ability to extract the main scene information and texture features. In order to solve the problem of poor style transfer, perceptual loss is introduced to constrain the model in terms of content and style. The pre-trained VGG is used to extract the content and style features to calculate the perceptual loss and, then, the loss can guide the model to generate landscape paintings with similar content to landscape photos and a similar style to target landscape paintings. In order to solve the problem of blurred outlines in generated landscape paintings, edge loss is proposed to the model. The Canny edge detection is used to generate edge maps and, then, the edge loss between edge maps of landscape photos and generated landscape paintings is calculated. The generated landscape paintings have clear outlines and details by adding edge loss. Comparison experiments and ablation experiments are performed on the proposed model. Experiments show that the proposed model can generate Chinese landscape paintings with clear outlines, rich details, and realistic style. Generated paintings not only retain the details of landscape photos, such as texture and outlines of mountains, but also have similar styles to the target paintings, such as colors and brush strokes. So, the generation quality of Chinese landscape paintings has improved. Full article

The electro-Fenton process is based on the generation of hydroxyl radicals (OH•) from hydroxide peroxide (H₂O₂) generated in situ by an oxygen reduction reaction (ORR). Catalysts based on carbon gels have aroused the interest of researchers as ORR catalysts due to their textural, chemical and even electrical properties. In this work, we synthesized metal-free electrocatalysts based on carbon gels doped with graphene oxide, which were conformed to a working electrode. The catalysts were prepared from organic-gel-based inks using painted (brush) and screen-printed methods free of binders. These new methods of electrode preparation were compared with the conventional pasted method on graphite supports using a binder. All these materials were tested for the electro-Fenton degradation of amoxicillin using a homemade magnetite coated with carbon (Fe₃O₄/C) as a Fenton catalyst. All catalysts showed very good behavior, but the one prepared by ink painting (brush) was the best one. The degradation of amoxicillin was close to 90% under optimal conditions ([Fe₃O₄/C] = 100 mg L⁻¹, −0.55 V) with the catalyst prepared using the painted method with a brush, which had 14.59 mA cm⁻² as J_K and a H₂O₂ electrogeneration close to 100% at the optimal voltage. These results show that carbon-gel-based electrocatalysts are not only very good at this type of application but can be adhered to graphite free of binders, thus enhancing all their catalytic properties. Full article

In this paper I propose to examine several poems by Elizabeth Bishop through the prism of the concept of letter delineated in “Lituraterre”, where Lacan explores the connection between the literal and the littoral in order to draw a key distinction between signifiers which are the semblances involved in ordinary communication, and the letter as a precipitate resulting from their breakdown. Insofar as the letter causes “writing effects that are structured around moments of vacillation of semblances” (M-H Roche), such effects may be traced in poems where Bishop focuses on how meaning is set adrift by eliding, displacing or transforming graphemes and phonemes. Her observation that “the names of seashore towns run out to sea” points to the littoral/liminal space of the poetic signifier that straddles enjoyment and meaning. I analyze Bishop’s painterly treatment of mist through the prism of Lacan’s discussion of Japanese calligraphy where the unary brush stroke, which “is the means to clear original Chaos” (E. Laurent), operates as the equivalent of the median void, often represented by fog in Chinese painting, i.e., as an avatar of the littoral that separates knowledge from enjoyment. I conclude with a reading of a poem where the semiosis of mortality hinges on the (dis-)appearance of certain phonemes, inviting us to question the literal/literary destiny of letters when they turn into Joycean litter, and prompting us to revisit Lacan’s familiar aphorism that “a letter always reaches its destination”. Full article

As immersive media, including VR, AR, MR, and XR, continues to expand rapidly during the pandemic era, there remains limited research on its comprehensive characteristics and its potential to create new forms of experience and aesthetics. This may be attributed to a lack of an understanding that immersive technologies exist encompassing both realms of reality and virtuality, leading to misconceptions that they are radically disconnected from traditional notions of materiality. In contrast, this study identifies an emerging trend characterized by the material implementation of immersive technologies in the domain of making culture in VR, which is referred to as “virtual craft” in this research. By reviewing studies on immersive media, materiality, making culture, and triadic semiotics, an integrated conceptual framework was developed to assess the experiences, aesthetics, and potential of immersive making culture. This framework is then applied to a specific case study involving virtual craft, with a particular focus on the 3D painting application, Tilt Brush, and related applications that the author has observed and tested. In conclusion, this paper presents a vision of the future of virtual craft and discusses the sustainability of immersive making culture, highlighting the potential for continued innovation and integration in various fields. Full article

Recent advances in soft polymer materials have enabled the design of soft machines and devices at multiple scales. Their intrinsic compliance and robust mechanical properties and the potential for a rapid scaling of the production process make them ideal candidates for flexible and stretchable electronics and sensors. Large-area electronics (LAE) made from soft polymer materials that are capable of sustaining large deformations and covering large surfaces and are applicable to complex and irregular surfaces and transducing deformations into readable signals have been explored for structural health monitoring (SHM) applications. The authors have previously proposed and developed an LAE consisting of a corrugated soft elastomeric capacitor (cSEC). The corrugation is used to engineer the directional strain sensitivity by using a thermoplastic styrene-ethylene-butadiene-styrene (SEBS). A key limitation of the SEBS-cSEC technology is the need of an epoxy for reliable bonding of the sensor onto the monitored surface, mainly attributable to the sensor’s fabrication process that comprises a solvent that limits its direct deployment through a painting process. Here, with the objective to produce a paintable cSEC, we study an improved solvent-free fabrication method by using a commercial room-temperature-vulcanizing silicone as the host matrix. The matrix is filled with titania particles to form the dielectric layer, yielding a permittivity of 4.05. Carbon black powder is brushed onto the dielectric and encapsulated with the same silicone to form the conductive stretchable electrodes. The sensor is deployed by directly painting a layer of the silicone onto the monitored surface and then depositing the parallel plate capacitor. The electromechanical behavior of the painted silicone-cSEC was characterized and exhibited good linearity, with an R${}^2$ value of 0.9901, a gauge factor of 1.58, and a resolution of 70 $\mathsf{\mu }\mathsf{\epsilon }$. This resolution compared well with that of the epoxied SEBS-cSEC reported in previous work (25 $\mathsf{\mu }\mathsf{\epsilon }$). Its performance was compared against that of its more mature version, the SEBS-cSEC, in a network configuration on a cantilever plate subjected to a step-deformation and to free vibrations. Results showed that the performance of the painted silicone-sCEC compared well with that of the SEBS-cSEC, but that the use of a silicone paint instead of an epoxy could be responsible for larger noise and the under-estimation of the dominating frequency by 6.7%, likely attributable to slippage. Full article

The Virgin Hodegetria, located in the Cathedral of Santa Maria Nuova in Monreale, near Palermo (Italy), probably dating the first half of the 13th century, is one of the earliest examples of medieval panel painting in Sicily. A diagnostic campaign was carried out on the panel aiming to identify the constituting materials and the executive technique, as well as to assess the state of conservation for supporting the methodological choice of the restoration intervention. Both non-invasive (X-ray radiography, digital microscope, multispectral imaging, ED-X-ray fluorescence) and micro-invasive (polarised light microscopy, ESEM-EDX, ATR-FTIR spectroscopy and micro-Raman spectroscopy) analyses were performed. According to the results, the executive technique followed the 13th–14th-century Italian painting tradition. A complex structure was applied on the wooden support, consisting of a double layer of canvas and several ground layers of gypsum and glue-based binder. The underdrawing was made by a brush using carbonaceous black pigment. The original palette includes red ochre, red lead, azurite, carbon black and bone black. During the several restorations, mercury-based red, indigo, smalt blue, orpiment and synthetic mars were used. The original silver leaf of the frame was covered with red tin-based lake and subsequently regilded with gold leaf. Proteinaceous and oil binders were also detected. Full article

Photocatalytic coatings based on TiO₂ nanoparticles have been applied to building materials over the past few decades, following encouraging results obtained by many laboratory studies and a few onsite testing campaigns showing their self-cleaning, antimicrobial and depolluting performance. However, these results clearly point out the need for a deeper understanding of the effectiveness of TiO₂-based treatments when applied over different substrates and their durability when exposed to an outdoor environment. The present paper investigates the behavior of a nanodispersion of titania nanoparticles applied to cement-based substrates. Cementitious materials are widely used in building façades, roofs, structures, roads and tunnels; hence, any improvement in their performance and/or the introduction of new and unique functionalities have potentially a very high impact on everyday life. A TiO₂ nanodispersion was applied by brushing and spraying on three cement-based substrates (a render, a prefabricated board and a painted prefabricated board), investigating its photocatalytic activity. Then, the samples were subjected to two artificially weathering procedures, involving rain washout and UV light exposure, and the changes in terms of the photocatalytic activity and contact angle were measured. The results suggest that the nature of the substrate plays a key role in the performance of the coating and that weathering has a significant impact too. Full article

Human handwriting is an everyday task performed regularly by most people. In the domain of robotic painting, multiple calligraphy machines exist which were built to replicate some aspects of human artistic writing; however, most projects are limited to a specific style of handwriting, often Chinese calligraphy. We propose a two-stage pipeline that allows industrial robots to write text in arbitrary typefaces and scripts using paintbrushes. In the first stage, we extract a set of strokes from character glyphs which are similar to how humans choose strokes during writing. In the second stage, we generate corresponding brush trajectories by applying a brush model to the extracted strokes. Our brush model computes the required brush pressure to achieve the given stroke width while also accounting for brush lag. We also present a method to automatically measure the parameters needed to predict brush lag by painting and recording calibration patterns. Our method generates trajectories for text in any given typeface, which, when executed by a robotic arm, results in legible written text. We can render most writing systems, excluding emoji and ligatures, in which arbitrary texts can be specified to write. Full article