Drawing the Dao: reflections on the application of Daoist theory of action in contemporary drawing practice

In this article, we engage resources in Daoist philosophy as a means for critically investigating theories of drawing in contemporary arts practice. The aims of this article are twofold. First, we highlight the problematic metaphysical assumptions that inform contemporary drawing practice and its theorization around ‘performance’. In particular, we criticize the tendency to conceive such performance in terms of transcendent or mystical expression, and relatedly, through notions of unthinking or pre-conceptual bodily practice. We suggest that such practices, and their corresponding theories, problematically bifurcate between ‘thinking’ and ‘unthinking’ action, thereby reinforcing a substance-based metaphysics. Second, in response to this problem, we begin to outline how Daoist philosophies of action might provide a more robust theorization for undertaking such practices. We consider the philosophical implications of what Hans-Georg Moeller has termed ‘the Dao Scenario’, as a model for critical practice that can avoid such problematic mysticism

Affirming fate and incorporating death: the role of 'amor fati' in Nishitani's 'Religion and nothingness'

This article argues for the usefulness of approaching specific aspects of Keiji Nishitani's thinking, in Religion and Nothingness, as developing out of a confrontation with central themes in the work of Friedrich Nietzsche. In particular, I interpret Nishitani's discussion of "the personal and impersonal" as a response to the issue of loving fate (amor fati) in Nietzsche's writings. I thus consider Nishitani's approach to amor fati as both a background for thinking through his critical relationship to Nietzsche and as a focal point for thinking through key insights in his creative appropriation of Zen

Carbon Nanotubes for Electronics and Energy

Ever since their discovery, carbon nanotubes have been touted as a new material for the future and a correspondingly lengthy list of possible applications are often cited in the literature. This excitement for carbon nanotubes is a result of their richly varying physical, electronic and optical properties, where it is possible to have single, double and multiple carbon walls with each wall potentially being either semiconducting or metallic and possessing unique optical transitions covering the ultraviolet to infrared spectral range. However, to date the realization of many of the proposed applications has been hindered by exactly the characteristic that made carbon nanotubes so attractive in the first place, namely the inherent inhomogeneity and varying properties of as-prepared or grown material. In order to become a true advanced material of the future, methods to prepare carbon nanotubes with defined length, wall number, diameter, electronic and optical property are necessary. Additionally, such methods to sort carbon nanotubes must afford high purity levels, be amenable to large-scale preparation and be compatible with subsequent integration into device architectures. In this work these issues are addressed with the use of gel based sorting techniques, which with the use of an automated gel permeation system allows for the routine preparation of milligram quantities of metallic and semiconducting carbon nanotubes, chirality pure single walled carbon nanotubes and even double walled carbon nanotubes sorted by their outer-wall electronic type. Having developed techniques to prepare large quantities, methodologies to control the order and orientation of this 1 D nanomaterial on the macro scale are developed. Inks of carbon nanotubes with liquid crystal concentrations and aligned films thereof are developed and this newfound control over the electronic and structural property opened the door for energy related applications. For example the use of thin films as the transparent electrodes in silicon:carbon nanotube solar cells or as the light harvesting layer in combination with fullerenes with the goal of creating an all carbon solar cell. Likewise on the few nanotube level the unique optical transitions of different nanotube chiralities are used in the fabrication of nanoscale photosensitive elements

Light emission, light detection and strain sensing with nanocrystalline graphene

Graphene is of increasing interest for optoelectronic applications exploiting light detection, light emission and light modulation. Intrinsically light matter interaction in graphene is of a broadband type. However by integrating graphene into optical micro cavities also narrow band light emitters and detectors have been demonstrated. The devices benefit from the transparency, conductivity and processability of the atomically thin material. To this end we explore in this work the feasibility of replacing graphene by nanocrystalline graphene, a material which can be grown on dielectric surfaces without catalyst by graphitization of polymeric films. We have studied the formation of nanocrystalline graphene on various substrates and under different graphitization conditions. The samples were characterized by resistance, optical transmission, Raman, X-ray photoelectron spectroscopy, atomic force microscopy and electron microscopy measurements. The conducting and transparent wafer-scale material with nanometer grain size was also patterned and integrated into devices for studying light-matter interaction. The measurements show that nanocrystalline graphene can be exploited as an incandescent emitter and bolometric detector similar to crystalline graphene. Moreover the material exhibits piezoresistive behavior which makes nanocrystalline graphene interesting for transparent strain sensors

Dry shear aligning: a simple and versatile method to smooth and align the surfaces of carbon nanotube thin films

Open Access Article. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.We show that the application of lateral shear force on a randomly oriented thin film of carbon nanotubes, in the dry state, causes significant reordering of the nanotubes at the film surface. This new technique of dry shear aligning is applicable to carbon nanotube thin films produced by many of the established methods

Carbon Nanotubes for Photovoltaics: From Lab to Industry

The use of carbon nanotubes (CNTs) in photovoltaics could have significant ramifications on the commercial solar cell market. Three interrelated research directions within the field are crucial to the ultimate success of this endeavor; 1) separation, purification, and enrichment of CNTs followed by 2) their integration into organic solar cells as a photosensitive element or 3) in silicon solar cells as a hole selective contact. All three subtopics have experienced tremendous growth over the past 20 years and certainly the performance of the silicon‐based cells is now rapidly approaching that of those on industrial production lines. With a view to these three research areas, the purpose of this Progress Report is to provide a brief overview of each field but more importantly to discuss the challenges and future directions that will allow CNT photovoltaics to move out of the research lab and into end user technology. These include efforts to upscale CNT purification, improvements in power conversion efficiency, increased light absorption, the identification of new material combinations, passivation strategies, and a better understanding of charge separation and energy transfer within these systems

Ternary PM6:Y6 Solar Cells with Single‐Walled Carbon Nanotubes

An organic solar cell with single-walled carbon nanotubes (SWCNTs) in the photoactive layer is typically a type II heterojunction with the semiconducting SWCNTs acting as the electron donor and C60 or other fullerene derivatives as the acceptor. Herein, the performance of solar cells consisting of (6,5) SWCNTs combined with C60 and three nonfullerene acceptors is evaluated in a bilayer architecture. SWCNTs are then combined with the donor/acceptor PM6:Y6 in a ternary mixture and both bulk heterojunction and bilayer devices are fabricated. The SWCNTs are found to extend the light absorption of PM6:Y6 solar cells into the infrared but their use must strike a balance between the SWCNT concentration to enhance light absorption and solvent-induced changes to the morphology of the active layer

Excitonic Resonances in Coherent Anti-Stokes Raman Scattering from Single-Walled Carbon Nanotubes

In this work we investigate the role of exciton resonances in coherent anti-Stokes Raman scattering (er-CARS) in single walled carbon nanotubes (SWCNTs). We drive the nanotube system in simultaneous phonon and excitonic resonances, where we observe a superior enhancement by orders of magnitude exceeding non-resonant cases. We investigated the resonant effects in five $(n,m)$ chiralities and find that the er-CARS intensity varies drastically between different nanotube species. The experimental results are compared with a perturbation theory model. Finally, we show that such giant resonant non-linear signals enable rapid mapping and local heating of individualized CNTs, suggesting easy tracking of CNTs for future nanotoxology studies and therapeutic application in biological tissues

Front and Back‐Junction Carbon Nanotube‐Silicon Solar Cells with an Industrial Architecture

In the past, the application of carbon nanotube-silicon solar cell technology to industry has been limited by the use of a metallic frame to define an active area in the middle of a silicon wafer. Here, industry standard device geometries are fabricated with a front and back-junction design which allow for the entire wafer to be used as the active area. These are enabled by the use of an intermixed Nafion layer which simultaneously acts as a passivation, antireflective, and physical blocking layer as well as a nanotube dopant. This leads to the formation of a hybrid nanotube/Nafion passivated charge selective contact, and solar cells with active areas of 1–16 cm$^{2}$ are fabricated. Record maximum power conversion efficiencies of 15.2% and 18.9% are reported for front and back-junction devices for 1 and 3 cm$^{2}$ active areas, respectively. By placing the nanotube film on the rear of the device in a back-junction architecture, many of the design-related challenges for carbon nanotube silicon solar cells are addressed and their future applications to industrialized processes are discussed

Principles of carbon nanotube dielectrophoresis

Dielectrophoresis (DEP) describes the motion of suspended objects when exposed to an inhomogeneous electric field. It has been successful as a method for parallel and site-selective assembling of nanotubes from a dispersion into a sophisticated device architecture. Researchers have conducted extensive works to understand the DEP of nanotubes in aqueous ionic surfactant solutions. However, only recently, DEP was applied to polymer-wrapped single-walled carbon nanotubes (SWCNTs) in organic solvents due to the availability of ultra-pure SWCNT content. In this paper, the focus is on the difference between the DEP in aqueous and organic solutions. It starts with an introduction into the DEP of carbon nanotubes (CNT-DEP) to provide a comprehensive, in-depth theoretical background before discussing in detail the experimental procedures and conditions. For academic interests, this work focuses on the CNT-DEP deposition scheme, discusses the importance of the electrical double layer, and employs finite element simulations to optimize CNT-DEP deposition condition with respect to the experimental observation. An important outcome is an understanding of why DEP in organic solvents allows for the deposition and alignment of SWCNTs in low-frequency and even static electric fields, and why the response of semiconducting SWCNTs (s-SWCNTs) is strongly enhanced in non-conducting, weakly polarizable media. Strategies to further improve CNT-DEP for s-SWCNT-relevant applications are given as well. Overall, this work should serve as a practical guideline to select the appropriate setting for effective CNT DEP