A 4 V Operation,Flexible Braille Display Using Organic Transistors,Carbon Nanotube Actuators,and Organic Static Random‐Access Memory

A sheet‐type Braille display operating at 4 V has been successfully fabricated by integrating organic an static random‐access memory (SRAM) array with carbon nanotube (CNT)‐based actuators that are driven by organic thin‐film transistors (control‐TFTs). The on current of organic control‐TFTs that drive CNT actuators exceeds 3 mA, the mobility exceeds 1 cm² V^?1s^?1, and the on/off ratio exceeds 10⁵ at an operational voltage of 3 V. By adjusting the process time for the formation of the aluminum oxide dielectrics, the threshold voltage of the organic TFTs can be systematically controlled. This technique leads to an improved static noise margin of the SRAM and enables its stable operation with a short programming time of 2 ms at a programming voltage of 2 V. As a demonstration of the operation of one actuator with one control‐TFT and SRAM: the displacement of actuator exceeds 300 μm at an operation voltage of 4 V, which is large enough for a blind person to recognize the pop‐up of braille dots. Integrating the SRAM array reduces the frame rate of a 12 dot × 12 dot display from 1/21.6 s to 1/2.9 s.     

The simulated moving-bed reactor for production of bisphenol A

Bisphenol A was produced from acetone and phenol over an ion-exchange resin catalyst at 50–90°C. Phenol was used as solvent. The reaction proceeded under the excess phenol condition. The reaction rate was proportional to the acetone concentration in the initial period of the reaction. After the acetone conversion exceeded approximately 50%, the reaction rate became lower than expected by the first-order reaction rate. This was ascribed to water adsorption onto the resin. Batch adsorption and breakthrough experiments showed that water was adsorbed approximately seven times stronger than acetone and that bisphenol A was not adsorbed. Using the reaction rate equation for bisphenol A production, the adsorption isotherms and overall mass transfer coefficients of the components, the numerical simulation of the 3-zone-type simulated moving-bed reactor was carried out. High resin flow rate was required in order to remove water out of the reaction zone, and a high liquid flow rate was also required to desorb water from the resin in the recovery zone. As far as the flow rates were set appropriately, water was successfully removed to prevent the catalyst deactivation and the long-term stable production of BPA was allowed.     

Ionic electroactive polymer actuators based on nano‐carbon electrodes

This review paper focuses on the recent studies of electroactive polymer actuators that have a triple‐layered configuration composed of an ionic‐gel electrolyte layer sandwiched by nano‐carbon dispersed ionic‐liquid gel electrode layers (bucky‐gel actuator) for the purpose of development of practical devices. The review covers recent studies of the developments of the materials of the bucky‐gel actuators and their electromechanical modeling. In the final section, the application to an ultra‐thin and ultra‐light Braille display based on the bucky‐gel actuator is described. © 2013 Society of Chemical Industry     

How contingent should a lifelike robot be? The relationship between contingency and complexity

We believe that lifelikeness is important to make it possible for a communication robot to interact naturally with people. In this research, the relationship between contingency and complexity in a lifelike robot was investigated. We have developed a robot control system to control experimentally contingency and complexity in interaction by combining a humanoid robot with a motion-capturing system. Two independent experiments were conducted with different levels of interaction complexity: simple interaction and complex interaction. Experiments in the simple interaction situation indicated that subjects felt that the robot behaved autonomously when contingency was low, and there was no significant relationship between contingency and a lifelike impression. On the other hand, experiments in the complex interaction situation showed that the robot gave the subjects the impression of being more autonomous and lifelike when contingency was high.     

Molecular Dynamics simulation of 〈 c + a 〉 dislocation core structure in hexagonal-close-packed metals

The core structures of 〈c+a〉 dislocations in hexagonal-close-packed (hcp) metals have been investigated by molecular dynamics (MD) simulation using a Lennard-Jones-type pair potential. The 〈c+a〉 edge dislocation has two types of core at 0 K; one is a perfect dislocation (type A), and the other has two 1/2 〈c+a〉 partials (type B). Type A transforms to type B by abruptly increasing temperature from 0 K to 293 K, while type B is stable in temperature range from 0 K to 293 K. In contrast, type A extends parallel to (0001) at 30 K, and this extended core is still stable at 293 K. These results suggest that the 〈c+a〉 edge dislocation glides on the as two 1/2 〈c+a〉 partial dislocations and becomes sessile, due to changes of the core structure. The 〈c+a〉 screw dislocation spreads over two planes at 0 K. The core transforms into a unsymmetrical structure at 293 K, which is spread over and , and core spreading occurs parallel to at 1000 K. A critical strain to move screw dislocations depends on the sense of shear strain. The dependence of the yield stress on the shear direction can be explained in terms of these core structures. This article is based on a presentation made in the symposium entitled “Dect Properties and Mechanical Behavior of HCP Metals and Alloys” at the TMS Annual Meeting, February 11–15, 2001, in New Orleans, Louisiana, under the auspices of the following ASM committees: Materials Science Critical Technology Sector, Structural Materials Division, Electronic, Magnetic & Photonic Materials Division, Chemistry & Physics of Materials Committee, Joint Nuclear Materials Committee, and Titanium Committee.     

DNA manipulation and retrieval from an aqueous solution with micromachined nanotweezers

We have demonstrated DNA handling with micromachined nanotweezers that consist of a pair of opposing nanoprobes and integrated thermal expansion microactuators for changing the probe gap. The probe tips coated with a thin Al layer were dipped into a droplet of a solution containing lambda-DNA molecules labeled with fluorescence dye, and then an ac electric field was applied between probes for several seconds. DNA molecules were then captured between the probe tips and retrieved from the solution to the air. The DNA capture between the probe tips could be performed more successfully on the droplet surface than in the underwater region. We also conducted an observation of the retrieved DNA molecules by transmission electron microscope and found that the thickness of the retrieved DNA molecules under the condition of this experiment was approximately 21 nm when the time of the applied ac power (1 MHz, 20 Vpp) was 20 s.     

Analysis of the visual Lombard effect and automatic recognition experiments

This study focuses on automatic visual speech recognition in the presence of noise. The authors show that, when speech is produced in noisy environments, articulatory changes occur because of the Lombard effect; these changes are both audible and visible. The authors analyze the visual Lombard effect and its role in automatic visual- and audiovisual speech recognition. Experimental results using both English and Japanese data demonstrate the negative effect of the Lombard effect in the visual speech domain. Without considering this factor in designing a lip-reading system, the performance of the system decreases. This is very important in audiovisual speech automatic recognition in real noisy environments. In such a case, however, the recognition rates decrease because of the presence of acoustic noise and because of the Lombard effect. The authors also show that the performance of an audiovisual speech recognizer depends also on the visual Lombard effect and can be further improved when it is considered in designing such a system.     

Social acceptance by senior citizens and caregivers of a fall detection system using range sensors in a nursing home

We developed a fall detection system with a status view function using range sensors in nursing homes and investigated how it was evaluated by seniors and caregivers about their intention to use and feelings of security. Our system calculates the positions and heights of seniors using range sensors for falling detection and sends an alert to the terminals of caregivers. Moreover, the system sends silhouette images from the range sensors that display the largest appearance of a person to the terminal to provide detailed information of seniors for the caregivers. In user evaluation, seniors and caregivers watched the three videos: simulated out-of-bed sensor, fall detection under constant observation and fall detection without constant observation. Participants answered questionnaires and were interviewed after watching each video. As a result, the seniors indicated significantly higher intention to use and feelings of security in the second and third videos than in the first video. Most seniors could accept being constantly monitored by the caregivers because they deemed safety to be more important than privacy. A few seniors (often healthy individuals) felt nervous under constant observation. Caregivers commented on the importance of flexibly switching the functions of the fall detection system to reflect individual status.     

Finding a person with a wearable acceleration sensor using a 3D position tracking system in daily environments

Person identification with accurate position information is essential for providing location-based services in real environments, such as a shopping mall. For this purpose, we propose a method that integrates 3D position information from environmental depth sensors and acceleration data from wearable devices to anonymously gather the trajectories of people who have wearable devices as well as others. Our proposed method identifies a person who has a wearable device by comparing two time series of acceleration data from device and position information. To do this, we extracted the behaviours of each axis using the changes of each bit of acceleration data at certain time periods. We evaluated our method with data collected at a shopping mall and a children’s playroom to investigate its effectiveness and robustness in different environments. Our evaluation results showed that it achieved an average identification of 85%, which is better than several alternative methods.