Direct Scribing Research Articles

Flexible battery-free wireless electronic system for food monitoring

Conventional battery powered and rigid wireless electronic systems are needed to be improved for adapting to the actual food quality and safety monitoring. This paper aims to propose and develop a flexible battery-free wireless electronic system (FBES) for food monitoring by the laser direct scribing on commercial polyethylene terephthalate/polyimide/copper (PET/PI/Cu) film. The FBES could acquire the temperature, weighing and pH sensor data, and transmit to the wireless reader by radio frequency identification/near field communication (RFID/NFC) with 13.56 MHz. The FBES could harvest the RF energy from the wireless reader and battery-free power for the food sensors and sensor acquisition module. The surface microscope image of the flexible Cu circuit demonstrated that the laser direct scribing could be easily applied to fabricate the flexible electronic system with low complex process and low cost. The food temperature, moisture loss rate (MLR) and pH monitoring applications have been evaluated. The application evaluation results demonstrated that the proposed FBES has a potential application for many kinds of food monitoring by harvesting the RF energy with continuous or on-demand. It could improve transparency and guarantee the quality and safety of food.

Laser In-Situ synthesis of metallic cobalt decorated porous graphene for flexible In-Plane microsupercapacitors

Transition metal nanoparticles-graphene nanocomposites incorporate the advantages of graphene and metal nanoparticles, which arouse extensive attention. Here, we design a novel, facile and versatile method for in-situ synthesis of laser-induced porous graphene (LIG) decorated with cobalt particles (Co). The LIG/Co nanocomposites are fabricated through one-step laser direct scribing on a customized film composed of polyimide (PI) powder, polyvinyl alcohol (PVA), and cobalt chloride (CoCl2·6H2O) precursors. Benefiting from the unique properties of Co nanoparticles embedded LIG, the obtained optimal in-plane micro-supercapacitors (IMSC) based on LIG/Co-1.5 possesses an excellent areal capacitance of 110.11 mF cm−2 and a superior energy density of 9.79 μWh cm−2, which are about 79 times that of pure LIG-based IMSCs. Simultaneously, the LIG/Co-1.5 MSCs also present good cycling stability, remarkable modular integration capability, and outstanding mechanical flexibility, showing potential for practical applications. Additionally, the density functional theory (DFT) calculations indicate that the decorating of cobalt particles elevates electron transfer. Moreover, the interaction between electrolyte and electrodes is also improved with the introduction of cobalt particles. Therefore, this strategy offers a new avenue for facile and large-scale manufacturing of various metallic atoms in-situ decorating in porous graphene.

Facile and Scalable Fabrication of High-Performance Microsupercapacitors Based on Laser-Scribed In Situ Heteroatom-Doped Porous Graphene.

This study proposes an efficient, facile, and scalable strategy to synthesize in situ heteroatom-doped porous graphene via laser direct writing on the precursor-doped polyimide (PI) film, which is fabricated for the first time through incorporating PI powder and precursors with sodium carboxymethyl cellulose (CMC) binder by a drop-casting and low-temperature drying process. The resulting microsupercapacitors (MSCs) based on the as-prepared heteroatom-doped porous graphene exhibit remarkable capacitive performance. The typical boron-doped MSC prepared on borax-doped polyimide film possesses an ultrahigh areal capacitance of 60.6 mF cm-2 at 0.08 mA cm-2, which is approximately 20 times larger than that of undoped MSC. Furthermore, the boron-doped MSC has impressive cycling stability (with the capacitance retention of 96.3% after 20 000 cycles), exceptional mechanical flexibility, tunable capacitance, and voltage output through arbitrary modular serial and parallel integration. Besides, the nitrogen-doped porous graphene with excellent capacitive performance is also prepared by laser direct scribing on the sulfonated melamine-doped polyimide film, demonstrating excellent scalability and generality of this strategy. Hence, one-step laser direct writing on precursor-doped polyimide films can realize in situ heteroatom doping and generation of hierarchical porous graphene electrodes simultaneously, which opens a new avenue for the facile, cost-effective, and scalable fabrication of heteroatom-doped porous graphene, thus promising for MSCs and various flexible and wearable electronics at large-scale production.

Academic and Personal Identity: Connection vs. Separation

ABSTRACT This article describes a qualitative study of faculty members’ personal versus academic identities based on interviews with 31 self-identified social work faculty members of diverse groups. Participants were recruited with consideration of the following: gender, gender identity and expression, sexual orientation, race, ethnicity, or religion, to explore the impact of connecting vs. separating one’s academic and personal identity. Data were collected using direct scribing which allows the researcher and participant to collaborate in the interview process. Social work faculty reported their experiences with identity management as it relates to interactions with students, colleagues, and administrators alike, as well as how it influences their teaching and research. Implications for social work education and the academy are considered.

Stories from LGBTQ social work faculty: What is the impact of being “out” in academia?

This article describes a qualitative study of 17 self-identified lesbian, gay, bisexual, transgender, and queer (LGBTQ) social work faculty members’ experiences with being “out” in an academic setting. Data were collected utilizing direct scribing, a method that promotes collaboration between the researcher and participants, allowing participants to edit their transcript in real time. Thematic analysis with inductive coding was used to identify three dominant themes: risks, rewards, and responsibilities associated with the decision to disclose one’s identity to students, colleagues, and superiors. Results indicate that most participants were open regarding their sexual orientation despite possible negative consequences as they reported feeling a sense of responsibility to self, students, colleagues, and the social work profession. Implications for social work teaching and research include evaluating practices in schools of social work to ensure they match the core values of our profession, including providing a safe environment for all students and faculty, valuing and promoting diversity, and modeling cultural competence through teaching and research.

Photon-collection improvement from laser-textured AZO front-contact in thin-film solar cells

With the objective of increasing light scattering and obtaining a higher light absorption in thin-film solar cells, we have textured aluminum-doped zinc oxide (ZnO:Al) films deposited by RF magnetron sputtering on glass substrates using a nanosecond pulsed laser working at 355 nm. The textures have been achieved by simply patterning the ZnO:Al surfaces through direct scribing, using either a linear pattern consisting of equally separated parallel grooves, or a crisscross pattern obtained by performing a second array of laser scribes perpendicular to the former. The relationship between the light scattering properties of the textured films and its morphology are discussed considering two different scattering sources: the pattern formed by the grooves that works as a diffraction grating, and a random roughness of low amplitude created during the laser process. To further characterize the textured samples, amorphous silicon solar cells were deposited onto ZnO:Al films with different textures and their spectral response and short-circuit current (Jsc) measured. An increment of 15% in Jsc compared to non-textured solar cells is achieved, with ample room for improvement.

Multilayer stack materials on silicon-based wafer dicing processes using ultraviolet laser direct dicing and milling methods

Sensing devices are crucial components in mobile devices for human health care and in industrial applications. Because of the recent increase in demand for sensing devices, manufacturers have shortened production cycles by using thinner silicon substrates or by integrating different integrated circuits onto wafers. In general, dicing quality (i.e., chipping, crack, residual, and groove widths) is vital for determining yield rate. Conventional blade dicing is a common method used in the wafer-dicing process that pollutes the cutting surface with debris generated from the dicing process and causes the cutting edge to crack easily. Laser dicing methods are strongly recommended because they have high processing accuracy and do not produce chemical pollution.In this study, a laser power versus dicing speed models were developed to determine whether laser direct scribing or laser milling is more suitable for wafer dicing. The dicing depth of the two methods were examined. An 8-in. silicon wafer with a 0.75-mm-thick multilayer stack material was diced using a nanosecond pulsed ultraviolet laser system with a 355-nm laser wavelength. The wafer was subsequently broken by using a die separation platform. The processing parameters included a laser power of 5.1, 8.05, 8.95, and 9.58 W at a dicing speed of 50, 100, 300, 500, and 700 mm/s, all of which were examined alongside the contour at the dicing edge to evaluate the dicing quality. Moreover, field-emission scanning electron microscopy and three-dimensional confocal microscopy were used to analyze the properties of the diced materials, including surface morphology and dicing depth, as well as the chipping, microcrack, debris, and residual widths. The results revealed a relationship between the dicing quality and processing parameters that could serve as a reference for microcutting multilayer stack materials on silicon wafers in on-line production processes.

It Should Not Be a Pit Stop: Voices and Perspectives of Homeless Youth on Labeling and Placement in Special Education

ABSTRACTAlthough the incomplete school histories of homeless youths are often highlighted, little is written about their school careers involving special education. This study is based on the educational narratives of homeless youths in special education. Their narratives were constructed using “direct scribing” and narrative ethnography. The article highlights the stigma and bullying experienced by youths as a result of being labeled, and shares their perspectives about special education being similar to a “pit stop”—a brief transitory stop with very short-sighted designs and benefits. It also discusses the benefits of direct scribing and the need to listen to the perspectives of students themselves on how labeling and placement in special education affect them.

Capturing/captured by stories of marginalized young people: Direct scribing and dialogic narrative analysis

Examining the results of the “narrative turn” in social work in their seminal article for Qualitative Research in 2005, Riessman and Quinney found themselves disappointed with the size and quality of the research corpus they reviewed. However, they also identified three exemplars of promising work, including the research of Faye Martin (Martin, 1998). Riessman and Quinney highlighted Martin’s narrative-gathering strategy, devised on the basis of her practice experience and dubbed “direct scribing.” The direct scribing method of narrative data collection disciplines the work of the researcher, who becomes the “scribe,” and elaborates the roles of the interviewees as authors of the narratives that they create. This article on capturing (and being captured by) the narratives of marginalized young people is situated in an increasingly significant movement in the social work literature that promotes giving voice to young people, so that they may have their views taken into account. We highlight the benefits of direct scribing as a means of narrative-gathering in social work and then address the challenge of interpreting these narratives, drawing on examples from our research. We suggest connections between direct scribing and the interpretive approach of dialogic narrative analysis as a method of interpretation that requires “letting stories breathe.” (Frank, 2010). The aim of this contribution is to describe specific ways in which linking direct scribing and dialogical narrative analysis may contribute to the advancement of narrative research in social work, and, in particular, to the enhancement of efforts to amplify “youth voice” in social work policy and practice.

Promoting and developing direct scribing to capture the narratives of homeless youth in special education

This article highlights the use of direct scribing to gather special education narratives of homeless youth. Direct scribing is a method of qualitative research developed in child welfare practice and adapted for research with foster youth. Its strengths include offering voice, power, and ownership of narratives to participants using minimal technology and the framework of narrativity. The article improves on the rigor of this method, highlighting considerations about “working up” or attention to interactional processes leading up to direct scribing, and the need to offer narrative power to participants. It offers a different take on interview practices including eye contact, listening, and the use of a computer screen as an interface. Through an extensive illumination of the narrativity of one participant, the preparation, process, and outcome of direct scribing are highlighted. The fit between social work values and this method is in keeping with advancing an anti-oppressive focus in research and practice.

Selective ablation with UV lasers of a-Si:H thin film solar cells in direct scribing configuration

Monolithical series connection of silicon thin-film solar cells modules performed by laser scribing plays a very important role in the entire production of these devices. In the current laser process interconnection the two last steps are developed for a configuration of modules where the glass is essential as transparent substrate. In addition, the change of wavelength in the employed laser sources is sometimes enforced due to the nature of the different materials of the multilayer structure which make up the device. The aim of this work is to characterize the laser patterning involved in the monolithic interconnection process in a different configurations of processing than the usually performed with visible laser sources. To carry out this study, we use nanosecond and picosecond laser sources working at 355 nm of wavelength in order to achieve the selective ablation of the material from the film side. To assess this selective removal of material has been used EDX (energy dispersive using X-ray) analysis, electrical measurements and confocal profiles. In order to evaluate the damage in the silicon layer, Raman spectroscopy has been used for the last laser process step. Raman spectra gives information about the heat affected zone in the amorphous silicon structure through the crystalline fraction calculation. The use of ultrafast sources, such as picoseconds lasers, coupled with UV wavelength gives the possibility to consider materials and substrates different than currently used, making the process more efficient and easy to implement in production lines. This approach with UV laser sources working from the film side offers no restriction in the choice of materials which make up the devices and the possibility to opt for opaque substrates.

Assessment of laser direct-scribing of a-Si:H solar cells with UV nanosecond and picosecond sources

Monolithical series connection of silicon thin-film solar cells modules performed by laser scribing plays a very important role in the entire production of these devices. Therefore a good characterization of the laser process, along with the assessment of different laser sources is compulsory. The current approach for laser scribing processes used in thin-film a-Si:H photovoltaic technology forces the use of transparent substrates [1]. In order to be able of keeping using laser for the module interconnection with other kind of substrates such as metal foil or plastic, the laser process must be performed in a direct scribing configuration, where the laser has to remove selectively the layers which make up the devices. In that sense, it is important to characterize the laser scribing process for different laser sources, owing to the different behaviour of the materials as a function of the laser parameters (wavelength, pulse width and pulse energy). In the current approach, the use of green wavelength (532 nm) is forced due to the strong dependency of the a-Si:H with this wavelength. This fact is leveraged for the two last laser steps of the monolithical interconnection of the cells, always in back-scribing configuration. On the other hand, for direct scribing configuration, the patterning must be obtained by means of selective ablation of the layers, and the morphologically affected area plays here an important role as well as the heat-affected zone. Thus, this work focuses on the use of UV laser sources working at two different temporal ranges of pulsewidth (nanosecond and picosecond) in order to eliminate the thermal affectation and improve the morphological quality of the groove.

Tales of transition: self‐narrative and direct scribing in exploring care‐leaving

Direct scribing is a technique that transforms oral discourse into written text, basically by typing oral material verbatim. It was developed in practice with youth in child welfare care and adapted for research data collection. The technique flattens the power imbalance in the interview situation and between oral speech and written text, supports self‐reflection, democratizes the ownership of written material, is potentially empowering, and is an efficient means to produce high‐quality text. The origins in practice are reviewed and a research application is discussed in detail. Thirty youths aged 18/19 from child welfare constructed self‐narratives about how they conceptualized and managed the adolescent transition, and collaborated with the researcher in analysing the narrative as a story. Each interview was direct scribed and printed copy given to the participant. Participants were introduced to direct scribing by completing a questionnaire presented on a note‐book computer, and some took part in a gender‐specific group discussion as a final data‐collection event, which was audio‐taped and transcribed. The value of direct scribing and self‐narrative in this research project and possibilities for other applications are discussed.