Low-cost Prototype Research Articles

Smart Home, Support At Old Age And Support For Persons With Disabilities: Speech Processing For Control Of Energy

Generally, conventional home wiring system use simple latching switch that is being connected to the power supply for controlling electrical appliances such as fan, light, washing machine, air conditioner and television. The switch is usually located at the wall near the electrical appliance. This requires the user to move to the location of the switches to control the appliances. There is rapid increase in the number of people with special needs like the elderly and the disabled. Smart houses are considered a good alternative for the independent life of older persons and persons with disabilities. A smart home is a home that provides its residents the comfort, the convenience and the ease of operation of devices at all times, irrespective of where the resident actually is within the house. Smart Homes include devices that have automatic functions and systems that can be remotely controlled by the user. The primary objective of a smart house is to enhance comfort, energy saving, security for the residents and independent living of people at old age and people with disabilities. A low-cost prototype of a voice controlled smart home system controlling four devices by an Arduino microcontroller via a four-channel relay is presented. Voice control is one of the easiest methods to give input commands and is a more personalized form of control, since it can be adapted and customized to a particular speaker’s voice. Voice recognition is a computer software program embedded in a hardware device with the ability to decode the human voice. Most voice recognition systems require “training” (also called “enrolment”) where an individual speaker reads text or isolated vocabulary into the system. The system analyses the person’s specific voices and uses it to fine-tune the recognition of that person’s command. Upon successful recognition of the voice command, the microcontroller drives the corresponding load with the help of the relay circuit. Voice or Speech Processing has been applied successfully for the control of the supply of energy to home appliances.

Field Collection of Geotechnical Measurements for Remote or Low-Cost Datalogging Requirements

Abstract Reliable, low-cost datalogging alternatives promote transfer of knowledge and technology to the wider geotechnical and geoscientist community. Alternative systems can ease increased data resolution on large projects, operate in remote locations with restricted site access, or allow developing countries access to reliable and cost-effective datalogging solutions. A low-cost prototype datalogger was developed and tested in the laboratory with the use of open-source materials. Open-source example code is provided at the permanent links included in this paper. The materials for the prototype were 20 % the cost of commercial datalogging units with similar capabilities. With labor, these custom-built units were 35–45 % the cost of a purchased datalogger. Measurements from commercial units and the prototype datalogger were compared to determine the prototype’s accuracy. The datalogger was deployed in place of commercially available dataloggers at three sites across western Canada in the past two years. Laboratory and field testing of the low-cost datalogger has shown the prototype to be easily adaptable to various sensor types. The study experimented with negative pore water pressure (matric suction), volumetric water content, and temperatures from SDI-12 sensors as well as positive pore water pressure and temperature from vibrating wire piezometers. Telemetry modules have been attached to remote dataloggers, transmitting occasional data points, and periodically verifying system operation. Assembly, installation, and monitoring with the low-cost datalogging system over the past two years has demonstrated their durability in field applications. The implementation of a low-cost, open-source geotechnical datalogging system can be a challenge in some locations and requires the consideration of limitations, which are addressed.

High-Temperature Additively Manufactured C-Band Antennas Using Material Jetting of Zirconia and Micro-Dispending of Platinum Paste

Additive manufacturing (AM) enables the development of rapid, low-cost prototypes for ad-hoc and on-demand manufacturing to repair and keep up the continuous operation of systems, especially in time-sensitive scenarios where the system recovery cannot wait for the shipment of new components. Therefore, the industry, military, and academia continue to invest in these technologies to potentially achieve novel 3D geometries based on high-temperature dielectric and conductors to endure harsh environments, such as commonly found in the oil and gas, defense, and aerospace sectors. This paper reports the electromagnetic properties of 3D-printed Yttria-Stabilized Zirconia (YSZ) for 2-6 GHz and the DC and RF effective conductivity of sintered platinum ink, where the dissipative losses of the additively manufactured coplanar waveguides (CPWs) are less than 0.05 dB/mm when the frequency is below 4 GHz. In addition, the AM CPWs are exposed to thermal cycling up to 600 ∘ to study the material’s thermal fatigue and potential degradation. However, the samples do not exhibit appreciable degradation after thermal cycling. Also, a two-layer back-fed antenna based on 3D-printed YSZ and platinum ink is designed, manufactured, and tested. Results show a measured gain of 2.5 dBi and a front-back ratio of 9.6 dB at 4.1 GHz.

Measurement of thermal conductivity in lightweight concrete produced with ground stone residue

With the advancement of concrete production technologies, such as the development of additives, use of different aggregates, dosing methods, mixing and application equipment, they have contributed to the emergence of concrete with special characteristics, as is the case with light concrete. Given the above, this research continues the experimental studies of structural lightweight concrete with expanded clay (coarse aggregate) developed by Lucas and Azambuja (2020). This research presents the results of mechanical properties at older ages, 28 days 214 days for Trait 1 (AN100%) and Trait 2 (AB20%) compared to the results of 7 days of age, however, the main contribution was the measurement of thermal conductivity with construction of a low-cost prototype in accordance with NBR 15220-4:2005, using the protected hot plate method. The results showed compressive strength values ​​of a minimum of 17,8 MPa at 7 days of age and a maximum of 28,6 MPa at 214 days, values ​​above 17 MPa established by NBR NM 35:1995 at 28 days, as well as the tensile strength by diametrical compression, which also presented values ​​that served as a basis for framing concrete as lightweight and structural. The evaluation of thermal conductivity was performed using a hot plate, in which the results were satisfactory between 0,44 and 0,71 W/(m.k), appropriate values ​​to answer the question of thermal performance, thus as well as complying with the established by ABNT NBR 15220-2:2008.

Development of a simple and low-cost prototype probe fully-compatible with atmospheric solids analysis probe for the analysis of human breath in real-time

The analysis in real-time of the exhaled breath has gained great attention in the last years due to the high number of possible applications, such as the investigation of endogenous compounds, the detection of disease biomarkers, or the determination of exogenous compounds related to the consumption of certain products. Although commercial ionization sources are already available for breath analysis, they require an important economic investment and/or complex setups. In this article, we describe a new probe developed at our laboratory, fully compatible with the Waters Corp. atmospheric solids analysis probe (ASAP), and where manufacturing is neither expensive nor complex. This atmospheric breath analysis probe (ABAP) can be directly used in Waters mass spectrometry instruments without the need of modifying the ionization source, the instrument or the ASAP, being also compatible with the software provided by the manufacturer. The ionization of the compounds is based on atmospheric pressure chemical ionization. The prototype has been successfully used in a high-resolution mass spectrometry system, and applied to the analysis of compounds present in human breath, as well as to the tentative identification of different substances present in foods and reported in exhaled breath after food consumption. Additionally, the ABAP has proven its applicability for the analysis in real-time of volatile compounds present in food using a purge-and-trap-like setup. Finally, ABAP could also be compatible with other ionization techniques, such as photoionization.

Low-cost camera-based pulsed and modulated continuous wave laser detection for laser-based optical communications

A novel, low-cost, camera-based method of detecting a single nanosecond (ns) laser pulse and kHz modulated continuous wave and pulsed lasers has been developed. The detector uses a simple optical modification to a standard rolling shutter color camera combined with image processing techniques to distinguish lasers from other illumination sources and extract a laser’s wavelength and pulse repetition frequency. In addition, the detector is also capable of detecting a single ns laser pulse at any given time. Such a detector has applications in free-space optical communications (FSO comms) as a low-cost broadband method of extracting information from multiple sources and as a detector of laser range finders. A low-cost prototype (≈£600) has been developed using entirely off-the-shelf components and assessed in laboratory and field trial conditions, with the ability to measure laser wavelengths to ±5 nm and pulse repetition frequencies to within ±5 % at a distance of 660 m. In the laboratory, the prototype was also able to detect each of the 1000 pulses generated by a 10 Hz 10 ns 532-nm pulsed laser, as well as 100 pulses sent at random intervals, highlighting its capability to detect a ns pulse at any given time. This novel technology offers a low-cost method of detecting lasers and extracting their pulse repetition frequencies, with a wide field of view and high spatial resolution. Ultimately, this technology has applications in FSO comms for between vehicles or platforms of interest, with a capability of communicating with multiple targets simultaneously.

Low-Profile and Dual-Polarization Water-Based Frequency Selective Rasorber With Ultrawideband Absorption

A low-profile and dual-polarization frequency selective rasorber (FSR) with an ultrawide absorption band is proposed. Based on the Mie resonance theory, water blocks with appropriate height are arranged as the lossy layer. The lossless layer is composed of a bandpass frequency-selective surface with Jerusalem-cross gaps. Utilizing the high loss of water, this rasorber can obtain ultrawideband absorption with a power absorptivity over 90% from 4.63 to 100 GHz, and the fractional bandwidth regarding the absorption band is over 182%. The insertion loss is 0.55 dB at 3 GHz under normal incidence and the thickness λ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">_m</i> (λ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">_m</i> being the free-space wavelength at the middle transmission frequency) is 0.077 λ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">_m</i> . The FSR also shows favorable stability of the frequency response over a relatively broad range of oblique incidence angles of 30° for dual-polarization. Compared with formal water-based FSR, this letter places emphasis on the novelty of elimination of the transition band and extended length of absorption band. Ultimately, a low-cost prototype of the presented design is fabricated, simulated, and measured to verify the feasibility.

Low-cost SARS-CoV-2 vaccine homogenization system for Pfizer-BioNTech covid-19 vials

&lt;p&gt;The current SARS-CoV-2 pandemic has been affecting all sectors worldwide, and efforts have been targeting the enhancement of people’s health and labour conditions of collaborators belonging to healthcare institutions. The recent vaccines emerging against covid-19 are seen as a solution to address the problem that has already killed up to two million people. The preparation of the Pfizer-BioNTech covid-19 vaccine requires a specific manipulation before its administration. A correct homogenization with saline solution is needed and, therefore, a manual process with a predefined protocol should be accomplished. This action can endanger the operators’ ergonomics due to the repetitive movement of the process. This paper proposes a low-cost prototype incorporating an arduino based embedded system actuating a servomotor to perform an autonomous vials’ homogenization allowing to redirect these healthcare workers to other tasks. Moreover, a contactless start order process was implemented to avoid contact with the operator and, consequently, the contamination. The prototype was successfully tested and recognised, and is being applied during the preparation of the covid-19 vaccines at the hospital pharmacy of &lt;em&gt;Centro Hospitalar de Vila Nova de Gaia/Espinho&lt;/em&gt;, &lt;em&gt;E.P.E.&lt;/em&gt;, Portugal. It can be easily replicated since the source files to assemble it are provided by the authors.&lt;/p&gt;

Design of an Antipodal Vivaldi Antenna Focusing on Constructional Aspects

This paper presents an Antipodal Vivaldi Antenna (AVA) design, focusing on its constructional aspects. The main features analysed are the connector attachment structure and the introduction of a polytetrafluoroethylene (PTFE) part that supports the antenna laminate. Issues related to dielectric penetration by milling tools are also addressed. The proposed AVA was manufactured through a low-cost prototyping process and tested, achieving an operational bandwidth from 5 to 18 GHz for a reflection coefficient less than −10 dB and an average gain of 6.23 dBi. The prototype meets all design requirements, which shows the viability of the developed radiator.

Low-cost and cleanroom-free prototyping of microfluidic and electrochemical biosensors: Techniques in fabrication and bioconjugation.

Integrated microfluidic biosensors enable powerful microscale analyses in biology, physics, and chemistry. However, conventional methods for fabrication of biosensors are dependent on cleanroom-based approaches requiring facilities that are expensive and are limited in access. This is especially prohibitive toward researchers in low- and middle-income countries. In this topical review, we introduce a selection of state-of-the-art, low-cost prototyping approaches of microfluidics devices and miniature sensor electronics for the fabrication of sensor devices, with focus on electrochemical biosensors. Approaches explored include xurography, cleanroom-free soft lithography, paper analytical devices, screen-printing, inkjet printing, and direct ink writing. Also reviewed are selected surface modification strategies for bio-conjugates, as well as examples of applications of low-cost microfabrication in biosensors. We also highlight several factors for consideration when selecting microfabrication methods appropriate for a project. Finally, we share our outlook on the impact of these low-cost prototyping strategies on research and development. Our goal for this review is to provide a starting point for researchers seeking to explore microfluidics and biosensors with lower entry barriers and smaller starting investment, especially ones from low resource settings.

The Field Guide to 3D Printing in Optical Microscopy for Life Sciences.

The maker movement has reached the optics labs, empowering researchers to create and modify microscope designs and imaging accessories. 3D printing has a disruptive impact on the field, improving accessibility to fabrication technologies in additive manufacturing. This approach is particularly useful for rapid, low-cost prototyping, allowing unprecedented levels of productivity and accessibility. From inexpensive microscopes for education such as the FlyPi to the highly complex robotic microscope OpenFlexure, 3D printing is paving the way for the democratization of technology, promoting collaborative environments between researchers, as 3D designs are easily shared. This holds the unique possibility of extending the open-access concept from knowledge to technology, allowing researchers everywhere to use and extend model structures. Here, it is presented a review of additive manufacturing applications in optical microscopy for life sciences, guiding the user through this new and exciting technology and providing a starting point to anyone willing to employ this versatile and powerful new tool.

Resolution-Enhanced Parallel Coded Ptychography for High-Throughput Optical Imaging

Ptychography is an enabling coherent diffraction imaging technique for both fundamental and applied sciences. Its applications in optical microscopy, however, fall short for its low imaging throughput and limited resolution. Here, we report a resolution-enhanced parallel coded ptychography technique achieving the highest numerical aperture and an imaging throughput orders of magnitude greater than previous demonstrations. In this platform, we translate the samples across the disorder-engineered surfaces for lensless diffraction data acquisition. The engineered surface consists of chemically etched micron-level phase scatters and printed sub-wavelength intensity absorbers. It is designed to unlock an optical space with spatial extent (x, y) and frequency content (kx, ky) that is inaccessible using conventional lens-based optics. To achieve the best resolution performance, we also report a new coherent diffraction imaging model by considering both the spatial and angular responses of the pixel readouts. Our low-cost prototype can directly resolve 308-nm linewidth on the resolution target without aperture synthesizing. Gigapixel high-resolution microscopic images with a 240-mm^2 effective field of view can be acquired in 15 seconds. For demonstrations, we recover slow-varying 3D phase objects with many 2{\pi} wraps, including optical prism and convex lens. The low-frequency phase contents of these objects are challenging to obtain using other existing lensless techniques. For digital pathology applications, we perform accurate virtual staining by using the recovered phase as attention guidance in a deep neural network. Parallel optical processing using the reported technique enables novel optical instruments with inherent quantitative nature and metrological versatility.

Integration and Prototyping of a Pulsed RF Oscillator with an UWB Antenna for Low-Cost, Low-Power RTLS Applications.

The goal of this paper is to present a compact low-cost and low-power prototype of a pulsed Ultra Wide Band (UWB) oscillator and an UWB elliptical dipole antenna integrated on the same Radio Frequency (RF) Printed Circuit Board (PCB) and its digital control board for Real Time Locating System (RTLS) applications. The design is compatible with IEEE 802.15.4 high rate pulse repetition UWB standard being able to work between 6 GHz and 8.5 GHz with 500 MHz bandwidth and with a pulse duration of 2 ns. The UWB system has been designed using the CST Microwave Studio transient Electro-Magnetic (EM) circuit co-simulation method. This method integrates the functional circuit simulation together with the full wave (EM) simulation of the PCB’s 3D model allowing fast parameter tuning. The PCB has been manufactured and the entire system has been assembled and measured. Simulated and measured results are in excellent agreement with respect to the radiation performances as well as the power consumption. A compact, very low-power and low-cost system has been designed and validated.

Development of a low-cost prototype

This study aims to develop a low-cost prototype to measure the mass and volumetric flow rate of fluids through the construction of a Pitot Tube. This meter must be able to measure the mass flow rate of air for different pressure values using only the water height level variation. For the development of the prototype, low-cost materials were used, in addition to some necessary tools. These experimental models are a didactic proposal for teaching and learning about the flow of fluids discipline, where it was verified that the experimental values found presented satisfactory results correlated with the theoretical concepts of an ideal fluid present in the literature. Thus, the Bernoulli and Torricelli equations were applied to assess the quality of the measurement method, to facilitate the learning of undergraduate students in the Production Engineering Course through conciliation between theory and practice in the Fluid Mechanics Laboratory discipline classes. Finally, the prototype experiment was exposed to other students at the institutional event called “I Integrar Produção” held by UFRA at the Parauapebas Campus.

A Wideband Termination Based on Laser-Scribed Lossy Microstrip Line Structures

Laser-direct writing has become an alternative method to fabricate microwave devices. We present a laser-scribed wideband open-end termination that relies on conductor loss of the microstrip line structure to obtain effective absorption. The proposed design consists of a resistive film overlapped on a strip conductor, providing an enlarged sheet-resistance range (20 Ω/□~1.2 kΩ/□) of the resistive film to reduce the fabrication difficulties. The resistive film is in tapered shape to enable small gradual changes in impedance, yielding minimized reflections (|S11|). The prototype is demonstrated utilizing the laser-direct writing technique, with a measured |S11| over −15 dB from 6 GHz to at least 30 GHz. The termination can also be used for attenuation over a −10 dB attenuation level (&gt;8.5 GHz) with a low reflection level better than −15 dB (&gt;2.0 GHz). This study can be employed for the applications where cheap wideband planar terminations are needed and promote fast, flexible, and low-cost prototyping or modification of the existing microwave circuits.

Autonomous underwater vehicle challenge: design and construction of a medium-sized, AI-enabled low-cost prototype

The design of an autonomous underwater vehicle (AUV) with physical dimensions of 1100 mm × 700 mm × 330 mm, and weight of 55 kg, is introduced herein. This paper describes the design, materials, hydrodynamics, and system architecture of an AUV prototype named Synoris, developed as a low-cost and medium-scale testbed platform. Synoris moves via six brushless motors, can reach up to 200 m depth, has an autonomy estimated around 6 hours and a modular design for multiple payload options. Stability control, autonomous movement, obstacle avoidance temperature/pressure sensing, and video/image capturing are simultaneously performed by exploiting a set of onboard computers that are described briefly in Section 4. The whole platform is built on top of the open source software called ROS (robotic operating system) that provides a flexible framework for writing robot software by providing services such as low-level device control, message parsing, data fusion, and system integration. Synoris is ideal for underwater applications and missions, involving machine learning and computer vision features. AUV development in general meets high-cost solutions due to the complexity and harshness of the operational environment. Even the most cost-effective solutions demand plentiful resources. This paper describes the entire process of development and how a relatively low-cost approach can provide a reliable AUV for many underwater applications, involving AI and machine-learning capabilities.

User Localization and Upstream Signaling for Beam-Steered Infrared Light Communication System

Beam-steered infrared light can provide ultra-high wireless capacity to individual user devices for indoor communication systems. The optical beams used to obtain such high capacities are relatively narrow with the average beam divergence of less than 2.55°, hence an accurate localization system to pinpoint multiple user devices at the same time is required. In addition, an indoor communication should provide mobile coverage to all users, therefore a dynamic and fast localization equipped with a capability of conveying the channel link status of the user devices to optical access points is necessary. In this work, we propose a vision-based technique to simultaneously localize the user devices in a room. A LED-tag system positioned around a photodetector enables the access points to recognize active users. A localization accuracy of 0.018° is achieved within milliseconds. Furthermore, taking advantage of this vision-based system, upstream signaling for channel status information is proposed using M-ary intensity modulation. Experimental results show that an upstream signaling rate of 2.4kbps can be achieved with our simple and low-cost prototype, enabling >10Gbit/s link per user.

Teaching equipment of newton’s second law

Mechanic is the branch of physics that is responsible for the study of the movement and balance of bodies in a system, within this can also be considered the bodies at rest. For the first case the scientist Isaac Newton considered the study of the movement of bodies, where he defines that any physical system which is subjected to different actions, as long as such actions are not nullified, will result in a change in the state of the body. The force is the magnitude that quantitatively measures the intensity, direction and direction of that interactions, having said that, if the summation of all forces of a system is different from zero, it can be concluded that the system will be in motion and therefore have an associated acceleration. Based on the above definition, was executed by the research group Design and Construction of Prototypes for Demonstration Experiments (DICOPED) in the design and construction of a prototype that allows to verify the Newton’s Second Law, looking to develop an autonomous, robust and low-cost prototype, that allows the use of the technology and tools present in the means, encourage and facilitate the teaching of basic concepts but no less important of physics to students of basic and higher education.

LOW COST SIMULATOR FOR CARDIOPULMONARY RESUSCITATION IN INFANTS

Introduction: The use of realistic simulation methodology is used in several learning scenarios, allowing students to participate directly in the problematization of situations that require immediate professional action. Objective: To develop, validate and validate a low cost simulator for cardiopulmonary resuscitation and resuscitation procedures in infants. Methods: An experimental study carried out with undergraduate students of the 1st year of the Nursing course at a higher education institution in the State of Paraíba, developed a simulator model with dimensions similar to an infant with low cost materials and made possible the use as a prototype for Basic Life Support training. The prototype was developed with the accessories for disengagement and cardiopulmonary resuscitation maneuvers. The data collection instrument was a questionnaire based on the American Hearth Association Basic Life Support guideline to enable and validate the Basic Life Support training instrument. Results: The low-cost prototype for Basic Life Support training was used as a learning object adequately and enabled the teaching-learning process as an accessible resource at low cost. Based on the questionnaire applied, we observed that there was an increase in the median number of correct answers and a reduction in the median of errors, which indicated an improvement in the acquisition of information and improvement in learning, observed through the test of Signal of Related Samples and the test of the Signs of Wilcoxon, (MA) and errors (ME), before and after training where it was found that there was an increase in MA and a reduction in ME with 5% significance (p &lt;0.001). The frequencies of response modifications after training with the simulator were also studied by means of the two-tailed McNemar test where Q1, Q2, Q3, Q4, Q8, Q9, Q13 and Q15 questions showed significant changes (p &lt;0, 05). Conclusion: A prototype was developed that simulated the training activity in Basic Life Support, which made it possible to carry out the procedures appropriately in positioning and simulation of cardiac resuscitation, mouth / nose ventilation, and tapping in the scapular region. Which allowed the validation of disengagement and resuscitation training as a low cost alternative for health education.

IoT‐based low‐cost prototype for online monitoring of maximum output power of domestic photovoltaic systems

This paper presents a low-cost prototype for monitoring online the maximum power produced by a domestic photovoltaic (PV) system using Internet of Things (IoT) technology. The most common tracking algorithms (P&O, InCond, HC, VSS InCond, and FL) were first simulated using MATLAB/Simulink and then implemented in a low-cost microcontroller (Arduino). The current, voltage, load current, load voltage, power at the maximum power point, duty cycle, module temperature, and in-plane solar irradiance are monitored. Using IoT technology, users can check in real time the change in power produced by their installation anywhere and anytime without additional effort or cost. The designed prototype is suitable for domestic PV applications, particularly at remote sites. It can also help users check online whether any abnormality has happened in their system based simply on the variation in the produced maximum power. Experimental results show that the system performs well. Moreover, the prototype is easy to implement, low in cost, saves time, and minimizes human effort. The developed monitoring system could be extended by integrating fault detection and diagnosis algorithms.