Pencil Trace Research Articles

Flexible supercapacitors based on a ternary composite of polyaniline/polypyrrole/graphite on gold coated sandpaper

Developing low-cost and efficient flexible supercapacitors is an important step towards the production of new energy storage systems for efficient wearable electronic devices. In this work, we report a simple and cost-effective approach to produce flexible electrodes for supercapacitors. The system consists of a complex ternary structure of hierarchical polyaniline (PAn) assembled on a polypyrrole (PPy) layer deposited on graphite pencil traces (Grt) in sandpaper. The proposed ternary composite PAn-PPy-Grt-Sp assembled in a device offered a maximal areal capacitance of 55.35 mF cm-2 at 0.3 mA cm−2, a higher value when compared to its counterparts of PAn-Grt-Sp (31.8 mF cm−2) and PPy-Grt-Sp (19.75 mF cm−2). The ternary composite also exhibited a higher energy (4.92 μWh cm−2) and power density (87.09 μW cm−2) at a current density of 0.3 mA cm−2 producing a more equilibrated supercapacitor device. The response to mechanical efforts returned negligible variation in electrochemical properties while cyclability remains as 80% of initial value after 3000 cycles.

Fine Art of Thermoelectricity.

A detailed study of hitherto unknown electrical and thermoelectric properties of graphite pencil traces on paper was carried out by measuring the Hall and Seebeck effects. We show that the combination of pencil-drawn graphite and brush-painted poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) films on regular office paper results in extremely simple, low-cost, and environmentally friendly thermoelectric power generators with promising output characteristics at low-temperature gradients. The working characteristics can be improved even further by incorporating n-type InSe flakes. The combination of pencil-drawn n-InSe:graphite nanocomposites and brush-painted PEDOT:PSS increases the power output by 1 order of magnitude.

An Origami Perovskite Photodetector with Spatial Recognition Ability.

Flexible photodetectors are attracting substantial attention because of their promising applications in bendable display and smart clothes which cannot be fulfilled by the existing rigid counterparts. In this work, we demonstrate a newly designed photodetector constructed on the common printing paper. Pencil trace was applied as the graphite electrode. With such a simple and convenient method, the as-prepared photodetector exhibited a satisfactory responsivity of 4.4 mA/W, on/off current ratio of 32, coupled with a high response speed of <10 ms. It also demonstrated excellent mechanical flexibility and durability. Most inspiringly, by an ingenious origami, we created the first perovskite photodetector with a 3D configuration. The cubic photodetector array displayed an excellent spatial recognition ability which could not be achieved in all the previously reported 2D photodetectors. Such a fusion of materials science and the art of origami provides a robust strategy for the design of low-cost flexible electronics, especially for the applications in 3D configurations.

Pencil-on-Paper Capacitors for Hand-Drawn RC Circuits and Capacitive Sensing

Electronic capacitors were constructed via hand-printing on paper using pencil graphite. Graphite traces were used to draw conductive connections and capacitor plates on opposing sides of a sheet of standard notebook paper. The paper served as the dielectric separating the plates. Capacitance of the devices was generally &lt; 1000 pF and scaled with surface area of the plate electrodes. By combining a pencil-drawn capacitor with an additional resistive pencil trace, an RC low-pass filter was demonstrated. Further utility of the pencil-on-paper devices was demonstrated through description of a capacitive force transducer and reversible chemical sensing. The latter was achieved for water vapor when the hygroscopic cellulose matrix of the paper capacitor’s dielectric adsorbed water. The construction and demonstration of pencil-on-paper capacitive elements broadens the scope of paper-based electronic circuits while allowing new opportunities in the rapidly expanding field of paper-based sensors.

Eco-friendly all-carbon paper electronics fabricated by a solvent-free drawing method

Here we report the fabrication of high-performance all-carbon temperature and infrared (IR) sensors with a solvent-free multiwalled carbon nanotube (MWCNT) trace as the sensing element and commercial graphite pencil trace as the electrical contact on recyclable and biodegradable cellulose filter paper without using any toxic materials or complex procedures. The temperature sensor shows a large negative temperature coefficient of resistance (TCR) in the range of −3100 ppm K−1 to −4900 ppm K−1, which is comparable to available commercial temperature sensors, and an activation energy of 34.85 meV. The IR sensor shows a high responsivity of 58.5 V W−1, which is greater than reported IR sensors with similar dimensions. A detailed study of the conduction mechanism in MWCNTs with temperature and the photo response with IR illumination was done and it was found that the conduction is due to thermally assisted hopping in band tails and the photo response is bolometric in nature. The successful fabrication of these sensors on cellulose filter paper with a comparable performance to existing components indicates that it is possible to fabricate high-performance electronics using low-cost, eco-friendly materials without the need for expensive clean-room processing techniques or harmful chemicals.

Pencil Drawn Strain Gauges and Chemiresistors on Paper

Pencil traces drawn on print papers are shown to function as strain gauges and chemiresistors. Regular graphite/clay pencils can leave traces composed of percolated networks of fine graphite powders, which exhibit reversible resistance changes upon compressive or tensile deflections. Flexible toy pencils can leave traces that are essentially thin films of graphite/polymer composites, which show reversible changes in resistance upon exposure to volatile organic compounds due to absorption/desorption induced swelling/recovery of the polymer binders. Pencil-on-paper devices are low-cost, extremely simple and rapid to fabricate. They are light, flexible, portable, disposable, and do not generate potentially negative environmental impact during processing and device fabrication. One can envision many other types of pencil drawn paper electronic devices that can take on a great variety of form factors. Hand drawn devices could be useful in resource-limited or emergency situations. They could also lead to new applications integrating art and electronics.

Pencil Traces

Review Article| October 01 2011 Pencil Traces: The Conversations of Composition Thomas L. Burkdall Thomas L. Burkdall Search for other works by this author on: This Site Google Pedagogy (2011) 11 (3): 598–602. https://doi.org/10.1215/15314200-1302881 Cite Icon Cite Share Icon Share Twitter Permissions Search Site Citation Thomas L. Burkdall; Pencil Traces: The Conversations of Composition. Pedagogy 1 October 2011; 11 (3): 598–602. doi: https://doi.org/10.1215/15314200-1302881 Download citation file: Zotero Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest search filter Books & JournalsAll JournalsPedagogy Search Advanced Search The text of this article is only available as a PDF. © 2011 by Duke University Press2011 Article PDF first page preview Close Modal Issue Section: Roundtable: Reviews of The Norton Book of Composition Studies, edited by Susan Miller You do not currently have access to this content.

Sketching interactive systems with sketchify

Recent discussions in the interaction design community have called attention to sketching as an omnipresent element of any disciplined activity of design, and have pointed out that sketching should be extended beyond the simple creation of a pencil trace on paper. More specifically, the need to deal with all attributes of a user experience, especially the timing, phrasing, and feel of the interaction, has been identified. In this article, we propose extending the concept of sketching with a pencil on paper to the more generic concept of fluent exploration of interactive materials. We define interactive materials as any piece of software or hardware that represents or simulates a part of the interactive user experience, such as input from sensors, output in the form of sound, video, or image, or interaction with Web services or specialized programs. We have implemented the proposed concept within Sketchify, a tool for sketching user interfaces. Sketchify gives designers the freedom to manipulate interactive materials by combining elements of traditional freehand sketching with functional extensions and end-user programming tools, such as spreadsheets and scripting. We have evaluated Sketchify in the education of interaction designers, identifying both successful aspects and aspects that need further improvements.

Recording sagittal condylar angles using a mandibular facebow

summary The aim of this study was to determine the average sagittal condylar inclination angles of dentate subjects using a mandibular facebow with pencil tracing styli, to relate these angles to values assigned to articulators, and to assess the repeatability accuracy of drawing a tangent to a traced curve. The right and left sagittal condylar inclination angles of 103 subjects were recorded using a mandibular facebow with pencil tracing styli which marked a graph card during protrusive excursions. Tangents to the tracings were measured with a protractor allowing assessment of reproducibility. The mean left and right sagittal condylar inclination angles were 32° and 31.5°, respectively, with no significant differences (P=0.609). Individual right and left measurements within each group showed significant differences (P= 0.0000). The mean of the tangents drawn through three sagittal condylar angle tracings by 10 operators was 33.3°, and the mean of 10 tangents drawn through the same three tracings by one of the authors was 32.9°, with no significant difference (P= 0.634). The average sagittal condylar inclination angles found in this study are in agreement with those reported in the literature. In fixed sagittal condylar angle articulators 30° appear to be an appropriate setting. The reproducibility of this method of recording sagittal condylar inclination angles was found to be accurate for the individual operator and between operators.

Recording sagittal condylar angles using a mandibular facebow.

The aim of this study was to determine the average sagittal condylar inclination angles of dentate subjects using a mandibular facebow with pencil tracing styli, to relate these angles to values assigned to articulators, and to assess the repeatability accuracy of drawing a tangent to a traced curve. The right and left sagittal condylar inclination angles of 103 subjects were recorded using a mandibular facebow with pencil tracing styli which marked a graph card during protrusive excursions. Tangents to the tracings were measured with a protractor allowing assessment of reproducibility. The mean left and right sagittal condylar inclination angles were 32 degrees and 31.5 degrees, respectively, with no significant differences (P= 0.609). Individual right and left measurements within each group showed significant differences (P = 0.0000). The mean of the tangents drawn through three sagittal condylar angle tracings by 10 operators was 33.3 degrees, and the mean of 10 tangents drawn through the same three tracings by one of the authors was 32.9 degrees, with no significant difference (P = 0.634). The average sagittal condylar inclination angles found in this study are in agreement with those reported in the literature. In fixed sagittal condylar angle articulators 30 degrees appear to be an appropriate setting. The reproducibility of this method of recording sagittal condylar inclination angles was found to be accurate for the individual operator and between operators.

Theories and error analysis of pencil tracing

To efficiently produce a more realistic image, the paraxial theory is introduced into computer graphics. The paraxial theory is a linear approximation theory established in other fields such as lens designing. The paraxial theory is formulated by a 4 × 4 matrix called “system matrix,” and this provides theoretical bases for various rendering methods such as pencil tracing, beam tracing, and cone tracing. This paper outlines the paraxial theory, analyzes errors from the viewpoint of its application to an image generation, and proposes a compact error-estimation function. The efficiency of the function is demonstrated experimentally. Basic data to develop an image-generation technology based on the paraxial theory are presented.

Principles and applications of pencil tracing

Pencil tracing, a new approach to ray tracing, is introduced for faster image synthesis with more physical fidelity. The paraxial approximation theory for efficiently tracing a pencil of rays is described and analysis of its errors is conducted to insure the accuracy required for pencil tracing. The paraxial approimation is formulated from a 4x4 matrix (a system matrix) that provides the basis for pencil tracing and a variety of ray tracing techniques, such as beam tracing, ray tracing with cones, ray-object intersection tolerance, and a lighting model for reflection and refraction. In the error analysis, functions that estimate approximation errors and determine a constraint on the spread angle of a pencil are given.The theory results in the following fast ray tracing algorithms; ray tracing using a system matrix, ray interpolation, and extended 'beam tracing' using a 'generalized perspective transform'. Some experiments are described to show their advantages. A lighting model is also developed to calculate the illuminance for refracted and reflected light.

A Contact-Pencil for Research on Writing

A pencil is described which closes a circuit when the lead is in contact with the writing surface. Its advantages over previous devices lie in simplicity, cost and reliability; it leaves a normal pencil trace on ordinary paper; and due to its novel mode of action, the movement of the writing element is extremely small, comparable with normal writing instruments.

Apparatus for the Remote Recording of Flow Conditions

SummaryAn instrument is described which detects total pressure, total temperature, and direction of flow simultaneously in a stream tube of one-sixteenth inch diameter. The observed directions and pressures are transmitted electrically to a remote station where they appear as pencil traces on a paper record which moves at a rate proportional to the traverse rate of the instrument. The temperature is noted at intervals and added manually to the trace. Integrators are included which permit rapid assessment of mean pressure and direction at the conclusion of a traverse, the control and maintenance of setting of the instrument being semi-automatic. A further development is also noted whereby total pressure and direction in three dimensions can be observed either manually, or remotely, by automatic means.

V. Magnetic declination at Kew Observatory, 1890 to 1900

In 1903 I carried out an analysis—referred to here for brevity as A—of the results given by the Kew magnetographs on “quiet” days during the 11 years 1890 to 1900. This investigation brought to light various novel phenomena. It was subsequently shown—in a paper to be referred to as B—that these phenomena are equally true of “quiet” days at Falmouth. Some of the phenomena suggested the possibility of differences of a certain kind between quiet days and other undisturbed days, and between ordinary days and disturbed days. To prosecute this enquiry, it was necessary to make an analysis of the data from all days at Kew from 1890 to 1900. Declination being the element of most practical interest, and least open to instrumental uncertainties, it was decided to treat it thoroughly in the first instance. In measuring the quiet day curves at Kew—a practice instituted in 1890—it has been usual to smooth them when any little irregularities occur, by drawing a free­- hand pencil trace following the general trend. It was decided, with some hesitation, to continue the practice, so that the results from all days should be as strictly comparable as possible with those from quiet days. The nature of the difficulties will be understood from the accompanying diagram. The continuous line curve ABCDEFQRS represents a hypothetical photographic record. The dotted line AB'C'R' represents the smoothed curve. When the object aimed at is the regular diurnal inequality, it will probably be generally conceded that the method of smoothing adopted is satisfactory so far as the wave-like portion ABCDE is concerned, at least so long as the interval of time corresponding to this portion is under an hour. If, how­ever, the times from A to B and from B to C were each an hour, the procedure would be disapproved by some authorities, who would argue that the free-hand curve should always be drawn so that its ordinate at any particular hour should represent the arithmetic mean of an infinite number of ordinates, uniformly distributed in time throughout the preceding and succeeding 30 minutes. It should, however, be remembered that the exact instant when an hour falls is really arbitrary. One observer may use Greenwich time, another local, and if the smoothing were carried out in accordance with the view last mentioned, it might make all the difference which choice happened to have been made. A disturbance such as QBS presents difficulties of another kind. If the time interval from Q to S is only a few minutes, and the general trend of the curve is very clearly shown, and closely similar to that of the average day, there can, I think, be little doubt that the best plan—at least when diurnal inequalities are concerned—is simply to disregard the disturbance altogether. If, however, the time from Q to S is considerable, and the general trend of the curve not clearly shown, the appropriate treatment is difficult to determine.