Electrically Activated Paper Actuators Hamedi, Mahiar M.; Campbell, Victoria E.; Rothemund, Philipp ...
Advanced functional materials,
April 19, 2016, Volume:
26, Issue:
15
Journal Article
Peer reviewed
Open access
This paper describes the design and fabrication of electrically controlled paper actuators that operate based on the dimensional changes that occur in paper when the moisture absorbed on the surface ...of the cellulose fibers changes. These actuators are called “Hygroexpansive Electrothermal Paper Actuators” (HEPAs). The actuators are made from paper, conducting polymer, and adhesive tape. They are lightweight, inexpensive, and can be fabricated using simple printing techniques. The central element of the HEPAs is a porous conducting path (used to provide electrothermal heating) that changes the moisture content of the paper and causes actuation. This conducting path is made by embedding a conducting polymer (PEDOT:PSS) within the paper, and thus making a paper/polymer composite that retains the porosity and hydrophilicity of paper. Different types of HEPAs (straight, precurved, and creased) achieved different types of motions (e.g., bending motion, accordion type motion). A theoretical model for their behavior is proposed. These actuators have been used for the manipulation of liquids and for the fabrication of an optical shutter.
Hygroexpansive electrothermal paper actuators (HEPAs) are fabricated from paper, conducting polymer and adhesive tape, and operate based on the moisture‐induced dimensional changes of paper. The central element of the HEPAs is a porous conducting path (used to provide electrothermal heating). A theoretical model for their behavior is proposed. These actuators can be used for the manipulation of liquids and for the fabrication of an optical shutter.
Lessons from an animal model that faithfully resembles human membranous nephropathy (MN) have informed our understanding of the pathogenesis of this organ-specific autoimmune disease and common cause ...of nephrotic syndrome. After it was established that the subepithelial immune deposits that characterize experimental MN form in situ when circulating antibodies bind to an intrinsic podocyte antigen, it was merely a matter of time before the human antigen was identified. The M-type phospholipase A2 receptor 1 (PLA2 R) represents the major target antigen in primary MN, and thrombospondin type 1 domain-containing 7A (THSD7A) was more recently identified as a minor antigen. Serologic tests for anti-PLA2 R and kidney biopsy specimen staining for PLA2 R show >90% specificity and 70% to 80% sensitivity for the diagnosis of primary MN in most populations. The assays distinguish most cases of primary MN from MN associated with other systemic diseases, and sequential anti-PLA2 R titers are useful to monitor treatment response. A positive pretransplantation test result for anti-PLA2 R is also helpful for predicting the risk for posttransplantation recurrence. Identification of target epitopes within PLA2 R and the genetic association of primary MN with class II major histocompatibility and PLA2R1 variants are 2 additional examples of our evolving understanding of this disease.
Background: Several student-centred and game-based approaches have developed in the last 40 years. Publications intended to describe the underlying theory and/or mechanics of each particular ...teaching/learning model have usually focused on modalities related to teacher-student interactions, taking into account the particular pedagogical content knowledge pertaining to the activities concerned. The extent to which a particular approach has students taking charge of their learning varies from one model to the other. Underlying learning theories, such as constructivism and nonlinear pedagogy, play an important role in explaining or justifying reasons for pedagogical choices. However, whatever approach is favoured by a teacher, there remains the matter of the regulation of learning in a student-centred teaching/learning environment.
Purpose: The main purpose of this paper was to discuss the regulation procedures implemented in a particular team-sport related teaching/learning strategy called the 'Tactical-Decision Learning Model' (T-DLM). A second and preliminary objective was to examine various AfL models with regard to the regulation of learning.
Scaffold of the paper: In the first section of the paper, a review of the literature is presented with regard to the diversity of the student-learning regulation construct, spreading from self-regulation to co-regulation and to shared/socially-shared regulation. In the second part of the paper, the authors discuss the regulation of tactical learning in team sports through the lens of T-DLM, considering the contribution of four basic features of the model: game-play in a small-sided game format, student observation, debate, road map, and their iterations.
Conclusion: In a team-sport teaching/learning context, cooperative learning becomes, by definition, the pivotal characteristic of the learning and learning-regulation processes. Although ever present, self-regulation is intermingled with socially shared regulation in the sense that each student's self-regulation activities voluntarily mingle with that of his/her teammates to bring about a collective action plan. Due to its socio-constructivist foundation and particular features, T-DLM offers many opportunities for socially-shared regulation of learning and may, given the right conditions, open the way for socially-shared metacognitive awareness of learning-regulation processes.
Purpose: The researchers discuss the debate of ideas (DoI) and student understanding conducted on questioning and student answers or discussions in game-based approaches and on DoI as used in the ...tactical-decision learning model. Literature Review: Literature regarding types of questions and expected student answers and questioning for learning in game-based approaches is reviewed. In addition, a brief overview of the context in which DoI was originally developed is presented. Findings and Discussion: Studies that used DoI are discussed with regard to the management of game play and observation, DoI content and the dynamics of student discussions, and impact on game play statistics and on students' tactical knowledge. Challenges for teachers and students are discussed, as a student-centered approach encourages changes in traditional teacher and student roles. Finally, the importance of understanding the internal logic of team sports for solving tactical problems and learning is discussed.
Objective
To validate the measurement properties and the detection performance of the FLARE‐RA questionnaire in a longitudinal prospective study.
Methods
To validate the FLARE‐RA self‐administered ...questionnaire, we conducted a prospective trial in rheumatoid arthritis (RA) patients to document: 1) content and construct validity by factor analysis, convergent validity by Pearson's correlation with routine assessment of patient index data (Routine Assessment of Patient Index Data 3 RAPID‐3 questionnaire), RA Impact of Disease (RAID) score, Disease Activity Score in 28 joints (DAS28), and Health Assessment Questionnaire (HAQ), 2) reliability (intraclass correlation coefficient ICC and Bland‐Altman plot), and 3) feasibility of use. Patients were examined and questionnaires were collected at baseline and 3 months, and every week in between for RAPID‐3.
Results
We recruited 138 patients from 13 centers: 81.9% women, mean age 57.4 years, mean DAS28 2.9, mean C‐reactive protein level 6.2 mg/liter, 84.4% rheumatoid factor positive, 78.0% anti–citrullinated protein antibody positive, and 78.8% with erosive disease. At baseline, the mean ± SD FLARE‐RA score was 2.3 ± 2.3. The content and construct validity of FLARE‐RA was good. A substantial floor effect, but no ceiling effect, was observed. Principal components analysis revealed 1 domain disentangled in 2 subdomains: physical and emotional. The FLARE‐RA total score was correlated with the DAS28 (r = 0.63, P < 0.001), RAID (r = 0.80, P < 0.001), RAPID‐3 (r = 0.77, P < 0.001), and HAQ (r = 0.53, P < 0.001). The ICC for reliability was 0.94 (95% confidence interval 0.92–0.96).
Conclusion
The FLARE‐RA self‐administered questionnaire represents a valid and valuable instrument to detect RA flare between visits to the physician.
Metallized paper is patterned to create touch pads of arrayed buttons that are sensitive to contact with both bare and gloved fingers. The paper‐based keypad detects the change in capacitance ...associated with the touch of a finger to one of its buttons. Mounted on an alarmed cardboard box, the keypad requires the appropriate sequence of touches to disarm the system.
The main objective of this work is to describe reaction–diffusion of two species in a porous medium. We aim at finding the macroscopic model equivalent to the description of the physics at the pore ...scale, with a peculiar attention to possible shape morphogenesis as introduced in Turing’s seminal article in 1952 (Turing in Philos Trans R Soc Lond Ser B 237:37,
1952
). The upscaling process makes use of the method of asymptotic expansions which takes advantage of the presence of the small parameter of separation of scales
ε
=
l
/
L
, where
l
and
L
are the characteristic sizes of the pores and the sample or the diffusion wavelength, respectively. Two different situations are investigated here: large reaction–diffusion and large diffusivity ratios. Among all possibilities, we investigate three orders of magnitude of the reaction terms and two orders of magnitude of the diffusivity ratio. In each of the situations, we demonstrate, if it exists, the macroscopic equivalent model at a scale
L
≫
l
, at the first order of approximation. Hence, we obtain a catalogue of macroscopic models for each considered case, their domain of validity, and the expression of the macroscopic properties. We underline the adequate conditions to account for the appearance of morphogenesis.
Mild, efficient, copper‐catalyzed N‐arylation procedures for nitrogen heterocycles, amides, carbamates, and C‐arylation procedures for malonic acid derivatives have been developed that afford high ...yields of arylated products with excellent selectivity. The N‐arylation of imidazole with aryl bromides or iodides was found to be greatly accelerated by inexpensive, air‐stable catalyst systems, combining catalytic copper salts or oxides with a set of structurally simple chelating ligands. The reaction was shown to be compatible with a broad range of aryl halides, encompassing sterically hindered, electron‐poor, and electron‐rich ones, providing the arylated products under particularly mild conditions (50–82 °C). The lower limit in ligand and catalyst loading and the scope of Ullmann‐type condensations catalyzed by complexes bearing those ligands with respect to the nucleophile class have also been investigated. Chelating Schiff base Chxn‐Py‐Al (1 c) generates a remarkably general copper catalyst for N‐arylation of pyrrole, indole, 1,2,4‐triazole, amides, and carbamates; and C‐arylation of diethyl malonate, ethyl cyanoacetate, and malononitrile with aryl iodides under mild conditions (50–82 °C). The new method reported here is the most successful to date with regard to Ullmann‐type arylation of some of these nucleophiles.
Cheap and copper! Ullmann‐type N‐ and C‐arylations of various nucleophiles were found to occur with high yields under particularly mild conditions by using inexpensive and air‐stable catalytic systems; these systems are composed of a combination of catalytic copper salts with a set of chelating ligands still not known to promote such reactions. The catalyst generated from chelating Schiff base 1 c is unique in terms of versatility. EWG=electron‐withdrawing group, EDG=electron‐donating group.
Firstly, a low operating temperature and high performance sensor for H
2
S detection based on α-Fe
2
O
3
/TiO
2
heterojunction nanoparticles (NPs) was developed by a liquid phase reaction with low ...synthesis temperature. Secondly, the microstructures and chemical compositions of the gas sensing material were analyzed by X-ray diffraction, scanning electron microscopy, transmission electron microscope, energy dispersive spectrometer and X-ray photoelectron spectra methods. Thirdly, with the 50 mol% α-Fe
2
O
3
doping amount and operating temperature of 120 °C, the gas sensing performances of the developed α-Fe
2
O
3
/TiO
2
NPs composite sensor to H
2
S were obtained: the responses of 3.4–15.6 to 1–50 ppm H
2
S, a linear relationship between the sensor response and the H
2
S concentration, the acceptable response/recovery time of 25 s and 48 s to 50 ppm H
2
S, excellent selectivity (10 times higher than those of the other tested gases) to H
2
S, and good repeatability and stability in 1-month duration. These excellent H
2
S gas sensing performances were attributed to the effects of n–n heterojunctions of two metal oxides, which were discussed in detail. Finally, the superior performances of the developed α-Fe
2
O
3
/TiO
2
NPs composite sensor were compared with the other reported H
2
S sensors, which the low operating temperature of 120 °C was highlighted.
This article describes the use of embossing and “cut-and-stack” methods of assembly, to generate microfluidic devices from omniphobic paper and demonstrates that fluid flowing through these devices ...behaves similarly to fluid in an open-channel microfluidic device. The porosity of the paper to gases allows processes not possible in devices made using PDMS or other nonporous materials. Droplet generators and phase separators, for example, could be made by embossing “T”-shaped channels on paper. Vertical stacking of embossed or cut layers of omniphobic paper generated three-dimensional systems of microchannels. The gas permeability of the paper allowed fluid in the microchannel to contact and exchange with environmental or directed gases. An aqueous stream of water containing a pH indicator, as one demonstration, changed color upon exposure to air containing HCl or NH3 gases.
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