Digital Watch Research Articles

An Efficient Implementation of Hybrid Carry Select Adder Using Parallel Prefix Addition and Binary to Excess 1 Conversion

One of the fastest adder architecture among the prevailing adder architectures. Adders are digital logic devices that add binary numbers together. They are commonly used as a component in an Arithmetic Logic Unit which itself is a component in Central Processing Unit. As a result any electronic device that has a Microcontroller or a CPU such as smart thermostats, digital alarm clock, digital wrist watches, and digital bathroom scales etc use adder circuit. In this work, we present an 8 bit hybrid Carry Select Adder architecture. It employs Parallel prefix addition using Kogge stone adder structure, Brent Kung adder structure, Han Carlson Adder structure and Ladner Fischer adder structures. It also employs Binary to Excess 1 code converter along with parallel prefix adders. Affirmation of the suggested design completed using Verilog code and simulated using Xilinx ISE 14.7 and the power, area and delay results were calculated using Cadence software. Comparisons with existing conventional adder architecture certify its better quality. The experimental analysis probes that the recommended hybrid carry select adder results threefold advantages in regards with speed, area and power.

High‐Performance Yarn Supercapacitor Based on Metal–Inorganic–Organic Hybrid Electrode for Wearable Electronics

AbstractA flexible all‐solid‐state yarn supercapacitor (YSC) based on metal–inorganic–organic ternary hybrid structure is fabricated by assembling polypyrrole@manganese oxide nanosheets@stainless steel yarn (PMS) yarn electrode of core/sheath/sheath configuration. The PMS yarn electrode combines the advantages of each component and shows excellent electrochemical performance, mechanical flexibility, and flame retardance owing to its unique structure and synergistic effect. The as‐fabricated YSC exhibits a high areal specific capacitance of 181 mF cm−2, areal energy density of 16.1 µWh cm−2, and areal power density of 10.3 mW cm−2. Moreover, the device possesses desirable voltage/current scalability and outstanding mechanical stability, which maintains 95.8% capacitance retention after 1000 bending cycles. As a demonstration, four YSCs are connected in series and then charged for 10 s to drive a light‐emitting diode (LED) digital watch. The outstanding overall performance of the YSC indicates that it is an ideal flexible power source for safe wearable electronics.

Skin-touch-actuated textile-based triboelectric nanogenerator with black phosphorus for durable biomechanical energy harvesting

Textiles that are capable of harvesting biomechanical energy via triboelectric effects are of interest for self-powered wearable electronics. Fabrication of conformable and durable textiles with high triboelectric outputs remains challenging. Here we propose a washable skin-touch-actuated textile-based triboelectric nanogenerator for harvesting mechanical energy from both voluntary and involuntary body motions. Black phosphorus encapsulated with hydrophobic cellulose oleoyl ester nanoparticles serves as a synergetic electron-trapping coating, rendering a textile nanogenerator with long-term reliability and high triboelectricity regardless of various extreme deformations, severe washing, and extended environmental exposure. Considerably high output (~250–880 V, ~0.48–1.1 µA cm−2) can be attained upon touching by hand with a small force (~5 N) and low frequency (~4 Hz), which can power light-emitting diodes and a digital watch. This conformable all-textile-nanogenerator is incorporable onto cloths/skin to capture the low output of 60 V from subtle involuntary friction with skin, well suited for users’ motion or daily operations.

Layered g-C3N4@Reduced Graphene Oxide Composites as Anodes with Improved Rate Performance for Lithium-Ion Batteries.

As important anodes in lithium-ion batteries, graphene is always faced with the aggregation problem that makes most of the active sites lose their function at high current densities, resulting in low Li-ion intercalation capacity and poor rate performance. To address this issue, a layered g-C3N4@reduced graphene oxide composite (g-C3N4@RGO) was prepared via a scalable and easy strategy. The resultant g-C3N4@RGO composite possesses large interlayer distances, rich N-active sites, and a microporous structure, which largely improves Li storage performance. It shows excellent cycle stability (899.3 mA h g-1 after 350 cycles under 500 mA g-1) and remarkable rate performance (595.1 mA h g-1 after 1000 cycles under 1000 mA g-1). Moreover, the g-C3N4@RGO electrode exhibits desired capacity retention and relatively high initial Coulombic efficiency of 58.8%. Impressively, this result is better than that of RGO (29.1%) and most of RGO-based anode materials reported in the literature. Especially, the g-C3N4@RGO-based electrode is enough to power two tandem red-light-emitting diodes and run a digital watch. Interestingly, the electronic watch can work continuously for more than 20 days. This novel strategy shows the great potential of g-C3N4@RGO composites as energy-storage materials.

Soft Tubular Triboelectric Nanogenerator for Biomechanical Energy Harvesting

AbstractA triboelectric nanogenerator (TENG), fabricated by soft materials with advantages of flexibility, stretchability, and water resistance, is a potential means for biomechanical energy harvesting. Herein, a soft tubular TENG (ST‐TENG) is proposed, which is composed of a flexible conductive sponge as the inner electrode and a soft silicone tube as the dielectric layer with the helix outer electrode. The ST‐TENG can be built in outsoles and harvest various biomechanical energy including pressing, bending, and twisting. The output performance of ST‐TENG was thoroughly investigated and the surface charge density can reach to 175.4 µC m−2. The ST‐TENG has stable and durable characteristics for 1.2 × 106 working cycles, 100 h soaking, and 5000 times bending. By walking or jogging with the ST‐TENG tubes, several portable electronics such as thermometer, digital watch, and calculator can be continuously powered. The soft energy harvester in this work has made a significant progress in self‐powered devices.

Numerical model for individual time calculation for evacuation among secondary students

PurposeThe purpose of this paper is to design a numerical model to calculate the individual evacuation time among secondary students based on Knowledge, Attitude and Practice (KAP), human characteristics and travel distances.Design/methodology/approachValidated KAP questionnaires were distributed among 290 respondents. The KAP level was obtained based on the assigned scores. During a fire drill, the individual evacuation time was calculated by using personal digital watch while the travel distances were recorded and measured. A linear numerical model was derived by using multiple linear regression to identify the significant variables and the coefficients.FindingsThe CVI, CVR and Cronbach’s α value (0.75, 0.59 and 0.7, respectively) which are greater than minimum accepted level proved the reliability and consistency of the instrument. The evacuation time prediction by the developed numerical model showed strong correlation with the actual time (R=0.95). The regression analysis found that 89 per cent proportion of variance in the evacuation time are determined by the predictors. Based on the linear equation, it found that the decrease in weight, knowledge level and walking speed while increase in BMI, flat and stair travel distances could increase evacuation time. From the six significant variables, weight, walking speed, flat and stair distances showed significant correlation in the model with p<0.001, while BMI and knowledge showed p<0.05. The integration with mobility factors expand the formula which applicable within dynamic fire scenario.Research limitations/implicationsThe involvement of examination students in the study is restricted by the Ministry of Education Malaysia to avoid interruption of learning session which limited the data representation.Originality/valueInstead of using the traditional direct measurement of the evacuation time, the developed numerical model is an alternative convenient approach which could be used as one of the pre-assessment tool to identify the level of safety among students. The low cost and shorter time application of this model become one of the greatest advantages compared to other available approaches. The calculated individual evacuation time could be used directly to develop a better fire safety policy.

A Compound Yarn Based Wearable Triboelectric Nanogenerator for Self‐Powered Wearable Electronics

AbstractWearable devices such as activity tracker, digital bracelet, and smartwatch become more and more popular. However, these devices need to be charged regularly due to the limited battery capacity. Therefore, it is important to develop a method to harvest mechanical energy from human motions to drive the wearable devices. Here, a wearable triboelectric nanogenerator (WTNG) based on compound yarns, which can be integrated well with clothing due to its good breathability and flexibility, is reported. The WTNG can be mass produced owing to the low cost and process maturity. Furthermore, the WTNG exhibits outstanding flexibility, breathability, and comfortability. The WTNG can generate a maximum short‐circuit current of 4 µA, delivering an instantaneous power density of 11.0 mW m−2 to an external load. Electronic devices such as digital watch and scientific calculator can be powered by a capacitor that is charged by WTNG. This work presents a significant step toward wearable electronics and will be a widely adopted technology in the near future.

Concurrent Harvesting of Ambient Energy by Hybrid Nanogenerators for Wearable Self-Powered Systems and Active Remote Sensing.

Harvesting energy available from ambient environment is highly desirable for powering personal electronics and health applications. Due to natural process and human activities, steam can be produced by boilers, human perspiration, and the wind exists ubiquitously. In the outdoor environment, these two phenomena usually exist at the same place, which contain heat and mechanical energies simultaneously. However, previous studies have isolated them as separate sources of energy to harvest and hence failed to utilize them effectively. Herein, we present unique hybrid nanogenerators for individually/simultaneously harvesting thermal energy from water vapors and mechanical energy from intermittent wind blowing from the bottom side, which consist of a wind-driven triboelectric nanogenerator (TENG) and pyroelectric-piezoelectric nanogenerators (PPENGs). The output power of the PPENG and the TENG can be up to about 184.32 μW and 4.74 mW, respectively, indicating the TENG plays the dominant role. Our hybrid nanogenerators could provide different applications such as to power digital watch and enable self-powered sensing with wireless transmission. The device could also be further integrated into a face mask for potentially wearable applications. This work not only provides a promising approach for renewable energy harvesting but also enriches potential applications for self-powered systems and wireless sensors.

Wearable Fabrics with Self-Branched Bimetallic Layered Double Hydroxide Coaxial Nanostructures for Hybrid Supercapacitors.

We report a flexible battery-type electrode based on binder-free nickel cobalt layered double hydroxide nanosheets adhered to nickel cobalt layered double hydroxide nanoflake arrays on nickel fabric (NC LDH NFAs@NSs/Ni fabric) using facile and eco-friendly synthesis methods. Herein, we utilized discarded polyester fabric as a cost-effective substrate for in situ electroless deposition of Ni, which exhibited good flexibility, light weight, and high conductivity. Subsequently, the vertically aligned NC LDH NFAs were grown on Ni fabric by means of a hot-air oven-based method, and fluffy-like NC LDH NS branches are further decorated on NC LDH NFAs by a simple electrochemical deposition method. The as-prepared core-shell-like nanoarchitectures improve the specific surface area and electrochemical activity, which provides the ideal pathways for electrolyte diffusion and charge transportation. When the electrochemical performance was tested in 1 M KOH aqueous solution, the core-shell-like NC LDH NFAs@NSs/Ni fabric electrode liberated a maximum areal capacity of 536.96 μAh/cm2 at a current density of 2 mA/cm2 and excellent rate capability of 78.3% at 30 mA/cm2 (420.5 μAh/cm2) with a good cycling stability. Moreover, a fabric-based hybrid supercapacitor (SC) was assembled, which achieves a stable operational potential window of 1.6 V, a large areal capacitance of 1147.23 mF/cm2 at 3 mA/cm2, and a high energy density of 0.392 mWh/cm2 at a power density of 2.353 mW/cm2. Utilizing such high energy storage abilities and flexible properties, the fabricated hybrid SC operated the wearable digital watch and electric motor fan for real-time applications.

Highly Transparent, Stretchable, and Self-Healing Ionic-Skin Triboelectric Nanogenerators for Energy Harvesting and Touch Applications.

Recently developed triboelectric nanogenerators (TENGs) act as a promising power source for self-powered electronic devices. However, the majority of TENGs are fabricated using metallic electrodes and cannot achieve high stretchability and transparency, simultaneously. Here, slime-based ionic conductors are used as transparent current-collecting layers of TENG, thus significantly enhancing their energy generation, stretchability, transparency, and instilling self-healing characteristics. This is the first demonstration of using an ionic conductor as the current collector in a mechanical energy harvester. The resulting ionic-skin TENG (IS-TENG) has a transparency of 92% transmittance, and its energy-harvesting performance is 12 times higher than that of the silver-based electronic current collectors. In addition, they are capable of enduring a uniaxial strain up to 700%, giving the highest performance compared to all other transparent and stretchable mechanical-energy harvesters. Additionally, this is the first demonstration of an autonomously self-healing TENG that can recover its performance even after 300 times of complete bifurcation. The IS-TENG represents the first prototype of a highly deformable and transparent power source that is able to autonomously self-heal quickly and repeatedly at room temperature, and thus can be used as a power supply for digital watches, touch sensors, artificial intelligence, and biointegrated electronics.

Liquid crystal displays, LC-materials and LPP photo-alignment

ABSTRACTThe invention of the twisted nematic liquid crystal display (TN-LCD) by Schadt and Helfrich in 1970 started the development of field-effect LCDs.Today, LCDs are the dominant flat panel display technology. Milestones in the ongoing research and development are sub-millisecond responding nematic liquid crystal (LC) materials, integration of silicon-driving electronics into display substrates, complex optical thin-films enabling excellent image quality and, last but not least, high resolution, contact-free photo-alignment/pattering of monomeric liquid crystals in displays and surface-aligned liquid crystal polymer (LCP) optical films. Photo-alignment of liquid crystal molecules by the linear photo-polymerization (LPP) technology enables high resolution, fast responding multi-domain LCDs with broad fields of view and complex, ultra-thin liquid crystal polymer retarder films. LCD-applications range from reflective displays for digital watches with virtually zero power consumption to large-area flat television screens with photographic resolution as well as to optical security elements and integrated optics devices. The commercial impact of the global LCD technology is illustrated by its annual turnover above $140billion.The seminar gives a personal overview of the multidisciplinary efforts between applied physics, material sciences and engineering which have enabled nematic liquid crystals of becoming the dominant flat panel display technology since 1970.

Development of the Digital Watch for Divers with Radio Controlled, Tough Solar Powered, and with Triple Sensor

Development of the Digital Watch for Divers with Radio Controlled, Tough Solar Powered, and with Triple Sensor

Comparison of on-line hemodiafiltration and high-flux hemodialysis for correcting calcium and phosphate metabolic disorder in uremia patients

Objective To compare the effect on correcting calcium and phosphate metabolic disorder and the impact on quality of life in uremia patients between on-line hemodiafiltration and high-flux hemodialysis. Methods 90 patients with uremia, digital watches were randomly divided into QL-HDF group and HFHD group, Ca2+ , P3+ , serum parathyroid hormone(PTH) level were measured before and after dialysis blood.The survival quality of patients were evaluated by the KDQOL-SFTM1.3 scale.The incidence of adverse reactions were collected.The similarities and differences of two groups were compared. Results The comparison of Ca2+ levels in the two groups before and after dialysis showed no significant difference(P>0.05); Of the QL-HDF group after treatment, P3+ was (1.82±0.19)mmol/L, PTH was (401.6±16.7)pg/L, which were significantly lower than those of QL-HDF group[P3+ (2.14±0.22)mmol/L, PTH(425.0±17.2)pg/L](t=24.256, 21.059, all P 0.05); 6 cases of adverse reactions was in the QL-HDF group (13.33%), 14 cases of adverse reactions was in the HFHD group(31.11%), there was significant difference between the two groups(χ2=5.361, P<0.05). Conclusion The two methods can improve the metabolic disorders of calcium and phosphorus in patients with uremia, and QL-HDF showed stronger ability to remove the ability, and the quality of life is higher, it is worth promoting in clinical practice. Key words: Calcium metabolism disorders; Phosphorus metabolism disorders; Uremia; Hemodiafiltration; Renal dialysis; Quality of life

A Complex Multilayer Screen-Printed Electroluminescent Watch Display on Fabric

A screen-printed electroluminescent (EL) digital watch display on fabric is presented. This paper demonstrates the process of creating interactive printed smart fabrics suitable for a broad range of applications. In order to control the display, a series of tracks were printed that are 400 μm wide with a pitch of 1 mm; these dimensions are lower than the previously reported literature for connections to an EL lamp. An optimized design for a bus bar layer is designed, modeled, and tested. The design improvement reduces the amount of the emitting area covered by an opaque conductor and is shown to have no negative impact on the function of the EL lamp. The design for the EL watch display includes 28 EL lamps on fabric forming four seven-segment displays. The display is the first demonstration of multiple EL seven-segment displays on fabric. The brightness is characterized and compared to commercially available blue EL lamps. The watch segments had similar brightness to commercially available lamps.

A self-sustaining pyroelectric nanogenerator driven by water vapor

Energy harvesting via pyroelectric nanogenerators (PNGs) is emerging as an attractive way to utilize waste heat. However, most of current PNGs need mechanical or electrical alternating devices to achieve the fast temperature oscillation, which is the key for PNGs to work. Herein we report a self-sustaining polymeric PNG driven by water vapor, without any energy-consuming alternating devices. Due to the high latent heat of water vapor, a fast temperature oscillation up to 23°C/s was achieved by automatic water condensation and evaporation on the surface of the PNG. Thus, the PNG based on commercial polyvinylidene difluoride polymer was able to output an open-circuit voltage of 145V and a short-circuit current of 0.12μA/cm2. The peak power density was 1.47mW/cm3 by volume and 4.12μW/cm2 by area, which is comparable to previously reported PNGs relying on alternating devices. Our PNG could provide uninterrupted electricity to drive a low-power electronic device (such as a digital watch) to work continuously. The electricity could also be stored in a capacitor for high-power tasks, such as flashing multiple blue LED lights once per minute. The self-sustaining PNG driven by water vapor provides a new strategy for efficiently recovering energy from hot water vapor that are wasted in industry and in our daily life.

Transformation of the Digital Watch: The evolution and what it signals

Over the span of 40+ years, the wristwatch has not changed significantly. Digital watches have the same basic functionality they have always had: time, date, alarm, and maybe a stopwatch. Aside from a small category of higher-priced, highly specialized digital watches geared toward extreme sports, watches have been a relatively inexpensive accessory.

George William Gray CBE MRIA FRSE. 4 September 1926 — 12 May 2013

George Gray was a renowned British materials chemist, internationally distinguished for his research into liquid crystals and their applications in flat-panel displays. His seminal invention of the liquid-crystalline cyanobiphenyls underpinned the creation of the modern electronic displays industry, which began with digital watches and has continued through to smart and three-dimensional televisions. There are now more liquid crystal displays in the world than people, and these devices have engendered societal changes through social networking on the Internet. His ability to design, synthesize and utilize self-organizing materials across the various disciplines of science showed that he was a supreme molecular engineer. For his contributions to soft-matter and related advanced technologies he was made a Commander of the British Empire, Kyoto Prize laureate, Fellow of the Royal Society, Fellow of the Royal Society of Edinburgh and Honorary Member of the Royal Irish Academy.

Wearable organic solar cells with high cyclic bending stability: Materials selection criteria

Despite the intrinsic flexibility of organic electronic materials due to their thinness, a deliberate selection of materials on the basis of their mechanical—not just charge-transport—properties is required for applications with mechanically demanding form factors, such as those that exist in the field of wearable electronics. This paper describes a skin-wearable solar cell enabled by the deliberate selection or intentional plasticization of the components to enable an extreme level of stability under cyclic bending deformations. In particular, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films plasticized with 10% fluorosurfactant are used for both the anode and cathode, with the cathode layer further modified with polyethyleneimine (PEI) to lower the work function. Use of poly(3-heptylthiophene) (P3HpT) instead of the far more common poly(3-hexylthiophene) (P3HT) as the electron donor permitted extreme deformation because of its increased mechanical compliance (owing to its low glass transition temperature). Cells fabricated on 13-µm polyimide tape and adhered to human skin show stable performance when compressively strained by approximately 75%. These compressive strains produce convex and concave buckles with minimum radii of curvature of ca. 100µm. Finite-element modeling predicts that the films require the ability to withstand a range of strains of 10%, when both convex and concave bends are considered. These devices, enabled by the stretchable semiconductor P3HpT, withstand up to one thousand cycles of compression with less than 20% degradation in power conversion efficiency, whereas devices based on P3HT show greater degradation after only five cycles, and fail catastrophically by fifty cycles. The usefulness of the wearable solar cells is demonstrated by their abilities to power an LED and a digital watch.

Apple Watch Temptation: Just visit the App Store

The watch is here? touts apple?s wearable computer online marketing slogan, implying that the one and only timepiece that really matters has arrived on the scene [1]. So much for the Rolex Cosmograph and Seiko World Timer when you can buy a stylish digital Apple Watch Sport or even an Apple Watch Edition crafted with 18-karat gold (Figure 1).

The Technophobe's Guide to the Digital Age.

### The Technophobe’s Guide to the Digital Age Douglas Adams had it right. In his Hitchhiker’s Guide to the Galaxy series he perfectly encapsulates the way I feel about technology. I am one of those poor Earthlings who ‘still thinks digital watches are a pretty neat idea,’1 and wonders why no one has noticed that technology is only making life more complicated? Adams’s infamous Nutrimatic-Drinks-Dispenser ‘invariably delivers a liquid that is almost, but not quite, entirely unlike tea.’1 And isn’t it true? Machines can’t even get tea right. When the best part of technology is the ‘sense of achievement you get from getting it to work at all,’2 something is wrong. Despite having been born slap-bang in the middle of the digital age, …