3,080 research outputs found
Highly Sensitive Soft Foam Sensors for Wearable Applications
Due to people’s increasing desire for body health monitoring, the needs of knowing humans’ body parameters and transferring them to analyzable and understandable signals become increasingly attractive and significant. The present body-sign measurement devices are still bulky medical devices used in settings such as clinics or hospitals, which are accurate, but expensive and cannot achieve the personalization of usage targets and the monitoring of real-time body parameters. Many commercial wearable devices can provide some of the body indexes, such as the smartwatch providing the pulse/heartbeat information, but cannot give accurate and reliable data, and the data could be influenced by the user’s movement and the loose wearing habit, either. In this way, developing next-generation wearable devices combining good wearable experience and accuracy is gathering increasing attention.
The aim of this study is to develop a high-performance pressure/strain sensor with the requirements of comfortable to wear, and having great electromechanical behaviour to convert the physiological signal to an analyzable signal
Design and fabrication of a long-life Stirling cycle cooler for space application. Phase 3: Prototype model
A second-generation, Stirling-cycle cryocooler (cryogenic refrigerator) for space applications, with a cooling capacity of 5 watts at 65 K, was recently completed. The refrigerator, called the Prototype Model, was designed with a goal of 5 year life with no degradation in cooling performance. The free displacer and free piston of the refrigerator are driven directly by moving-magnet linear motors with the moving elements supported by active magnetic bearings. The use of clearance seals and the absence of outgassing material in the working volume of the refrigerator enable long-life operation with no deterioration in performance. Fiber-optic sensors detect the radial position of the shafts and provide a control signal for the magnetic bearings. The frequency, phase, stroke, and offset of the compressor and expander are controlled by signals from precision linear position sensors (LVDTs). The vibration generated by the compressor and expander is cancelled by an active counter balance which also uses a moving-magnet linear motor and magnetic bearings. The driving signal for the counter balance is derived from the compressor and expander position sensors which have wide bandwidth for suppression of harmonic vibrations. The efficiency of the three active members, which operate in a resonant mode, is enhanced by a magnetic spring in the expander and by gas springs in the compressor and counterbalance. The cooling was achieved with a total motor input power of 139 watts. The magnetic-bearing stiffness was significantly increased from the first-generation cooler to accommodate shuttle launch vibrations
Piezoelectric microsensors for semiochemical communication
Chemical communication plays vital role in the mediating the behaviour
of an organism living in the “odour space”. The mechanisms by which
odours are generated and detected by the organism has evolved over
thousands of years and thus the potential advantages of translating this
system into a fully functional communication system has opened new
avenues in the area of multi-disciplinary research. This formed the basis
of the Biosynthetic Infochemical Communications project – iCHEM
whose central aim was to develop a new class of communication
technology based on the biosynthesis pathways of the moth, S. littoralis.
This novel infochemical communication system would consist of a
“chemoemitter” unit which would generate a precise mix of infochemicals
which after travelling through the odour space would be detected by a
complementary tuned detector – the “chemoreceiver” unit comprising of
a ligand specific detection element and an associated biophysical model
functioning similar to the antennal lobe neuron of the moth. This
combined novel system will have the capability of communicating by the
help of chemicals only, in the vapour or liquid phase. For the work
presented in this thesis, the novel concept of infochemical
communication has been examined in the vapour and liquid phase by
employing piezoelectric microsensors. This has been achieved and
demonstrated throughout the thesis by employing chemo-specific
acoustic wave microsensors. For vapour phase assessment, quartz
crystal microbalance, were coated with different organic polymer
coatings and incorporated in a prototype infochemical communication
system detecting encoded volatiles. For liquid phase assessment, shear
horizontal surface acoustic wave (SH-SAW) microsensors were
specifically designed and immobilised within Sf9 insect cells. This GPCR
based whole cell biosensing system was then employed to detect ligand
specific activations thus acting as a precursor to the development of a
fully functionalised OR based signalling system, thus contributing to the
growing field of communication and labelling technology
NASA patent abstracts bibliography: A continuing bibliography. Section 1: Abstracts (supplement 40)
Abstracts are provided for 181 patents and patent applications entered into the NASA scientific and technical information system during the period July 1991 through December 1991. Each entry consists of a citation, an abstract, and in most cases, a key illustration selected from the patent or patent application
User needs, benefits and integration of robotic systems in a space station laboratory
The methodology, results and conclusions of the User Needs, Benefits, and Integration Study (UNBIS) of Robotic Systems in the Space Station Microgravity and Materials Processing Facility are summarized. Study goals include the determination of user requirements for robotics within the Space Station, United States Laboratory. Three experiments were selected to determine user needs and to allow detailed investigation of microgravity requirements. A NASTRAN analysis of Space Station response to robotic disturbances, and acceleration measurement of a standard industrial robot (Intelledex Model 660) resulted in selection of two ranges of low gravity manipulation: Level 1 (10-3 to 10-5 G at greater than 1 Hz.) and Level 2 (less than = 10-6 G at 0.1 Hz). This included an evaluation of microstepping methods for controlling stepper motors and concluded that an industrial robot actuator can perform milli-G motion without modification. Relative merits of end-effectors and manipulators were studied in order to determine their ability to perform a range of tasks related to the three low gravity experiments. An Effectivity Rating was established for evaluating these robotic system capabilities. Preliminary interface requirements were determined such that definition of requirements for an orbital flight demonstration experiment may be established
Smart polymeric temperature sensors – for biological systems
The damaged brain is vulnerable to increase in brain temperature after a severe head injury. Continuous monitoring of intracranial temperature depicts functionality essential to the treatment of brain injury Many innovations have been made in the biomedical industry relying on electronic implants in treating condition such as traumatic brain injury (TBI) or other cerebral diseases. Hence, a methodical and reliable way to measure the temperature is crucial to assess the patient’s situation. In this investigation, an analysis of various approaches to detect the change in the temperature due to resistance, current-voltage characteristics with respect to time has been evaluated. Also, studies describing various materials used in sensors, their working principles and the results anticipated in these discrete procedures are presented. These smart temperature sensors have provided the accuracy and the stability compared to earlier methods used to detect the change in brain temperature since temperature is one of the most important variables in brain monitoring
Recent Advances in Printed Capacitive Sensors
In this review paper, we summarize the latest advances in the field of capacitive sensors
fabricated by printing techniques. We first explain the main technologies used in printed electronics,
pointing out their features and uses, and discuss their advantages and drawbacks. Then, we review
the main types of capacitive sensors manufactured with different materials and techniques from
physical to chemical detection, detailing the main substrates and additives utilized, as well as the
measured ranges. The paper concludes with a short notice on status and perspectives in the field.H2020-MSCA-IF-2017-794885-SELFSEN
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