Low-cost Circuitry Research Articles

Hybrid sooty tern naked mole-rat algorithm and Fuzzy Type-2 logic-based trust and energy-aware stable clustering protocol

With the advent of low-cost circuitry, sensor and communication technologies, it is feasible to sense and communicate the condition of surroundings to end user. The wireless networks of these circuits, called Wireless Sensor Network (WSN) that are utilized in a multitude of applications such as in hospitals, smart industries, environmental sensing and military protection. WSN's main issue is efficient data sharing between various sensors and efficient communication with sink. However, in the real-world sensors have restricted range of communication and resources, which in turn imposes constraints for successful coordination in the design of the communication strategy. Investigating the trust level of a node is also a significant aspect of WSNs using which two sensor nodes can communicate since an untrustworthy node has adverse effect on the reliability and quality of data. The biggest challenge in this domain is to devise a suitable communication system that helps sensors to achieve their target with minimal energy loss and high confidence level transmission of the full exploration data. Clustering is an effective way to extend the network performance parameters. In order to address the restrictions in these protocols such as cluster head (CH) lifetime, cluster quality etc.; an enhanced routing protocol with optimum CH selection algorithm and trust management are required to design an efficient WSN framework. A hybrid sooty tern naked mole rat algorithm (STNMRA) is developed to mitigate the effect of local stagnation problem in classical naked mole rat algorithm (NMRA). In order to evaluate the effectiveness of proposed STNMRA, highly challenging CEC 2019 numerical test problems are taken into consideration and statistical test validates that STNMRA provides better results with respect to competitive algorithms. STNMRA based clustering protocol using a Fuzzy Type-2 logic is proposed in this paper to enhance the trust level and thus the network lifetime. The proposed clustering protocol outperforms state-of-the-art techniques in terms of the efficient removal of malicious nodes together with improved network lifespan and reduced energy consumption.The source code for the proposed algorithms is available at: https://github.com/mittalnitinsvsu/STNMRA.

Application-aware aging analysis and mitigation for SRAM Design-for-Relability

Most embedded systems integrate several on-chip Static Random Access Memories (SRAMs). These SRAMs are increasingly susceptible to reliability threats such as Bias Temperature Instability (BTI) due to the continuous trend of technology shrinking. BTI leads to a significant performance degradation, especially in the Sense Amplifiers (SAs) of SRAMs, where failures are fatal, since the data of a whole column is destroyed.In this paper we present a new workload-aware aging analysis for On-Chip SRAMs. The method incorporates the workload of embedded applications while considering aging in the complete read-path and its control signals. According to this workload, we predict the performance degradation in the memory and its end of lifetime. Furthermore, we present the Mitigation of AGIng Circuitry (MAGIC), a low-cost circuitry to effectively mitigate aging in SAs by wear-leveling.We show that SRAM cell and SA aging have a significant contribution to the overall degradation of the read-path while aging in the SA's control signals counter-intuitively leads to minor performance improvements. The proposed mitigation scheme MAGIC can mitigate the degradation in the read-path up to ∼26% while introducing minimal area/performance overhead. Our application-aware end-of-life analysis shows that this translates into 3x longer lifetime.

Enhancement in operational current of PTB7 based ammonia gas sensor utilizing F4-TCNQ as P-type dopant

We demonstrate a (poly[(4,8-bis(2-ethylhexyloxy)-benzo-(1,2-b:4,5-b)dithiophene)− 2,6-diyl-alt-(4-(2-ethylhexyl)− 3-fluorothieno[3,4-b]thiophene-)− 2-carboxylate-2,6-diyl)]) (PTB7) based ammonia gas sensor with high operational current up to 10−4 A. Using (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) (F4-TCNQ) as a p-type dopant for PTB7, the operation current under driving voltage of 5 V was effectively increased to 1.5×10−4 A, while that of a standard device was only 3×10−6 A. According to the study of space-charge-limited current and ultraviolet photoemission spectroscopy (UPS), the enhanced operational current can be attributed both to the higher mobility and lower carrier injection barrier of the F4-TCNQ doped PTB7. Detailed comparative analysis between the F4-TCNQ doped sensor and the non-doped sensor was also studied. The increased operational current and the current drop during sensing of the F4-TCNQ doped sensors are both beneficial to the realization of low-cost circuitry sensing system, which demonstrates the potential of the strategy of utilizing p-type doping in organic gas sensors for the developing of affordable point-to-care (POC) devices.

Design and Evaluation of a Low-Cost SAW Resonator Read-Out System at 2.4 GHz

The functionality of using surface acoustic wave (SAW) resonators in wireless sensing applications has been demonstrated in many publications. When used, their resonance frequency has to be determined with a precision of up to 10 ppm with measurement periods in the microsecond range. For this purpose, the so-called instantaneous frequency measurement (IFM) can be used, which uses a six-port receiver to measure a frequency-dependent phase delay. This work presents a system that incorporates an alternative low-cost circuitry that multiplexes the four six-port outputs on only one detection circuitry with the help of an RF switch. This reduces the system cost and eliminates the measurement errors otherwise caused by differing gain and group delay values in the baseband filters. Based on this idea, a complete SAW readout system is presented and experimentally evaluated, which also can be used as a sensor node as it incorporates a Bluetooth interface. The shown measurement results demonstrate that the system can achieve a precision of 7.9 ppm concerning frequency measurement at an update rate of 41.7 Hz, demonstrating the feasibility of the alternative detection circuit.

A Novel Time-to-Amplitude Converter and a Low-Cost Wide Dynamic Range FPGA TDC for LiDAR Application

This paper demonstrates a low-cost wide dynamic range FPGA time-to-digital converter (TDC) and a time-to-amplitude converter (TAC) based on an embedded XOR gate of the FPGA and a low-complexity circuitry. TACs and TDCs are important for distance measurements in LiDAR systems in a wide range of applications from self-driving cars to topographic mapping. LiDAR’s high cost, relatively large size and complexity are important implementation challenges that need to be addressed. In the literature, external circuits are used to provide low phase noise clock signals into the FPGA TDC to measure long range time intervals adding to the complexity and cost. Our TDC can measure a wide dynamic range of 1 ms with high precision using a low-cost FPGA board. Calibration using dynamic phase-shifting (DPS) is conducted with a resolution of 18 ps. The performance measurements gave us insight on the relative temperature insensitive regions for operating the TDC. The ideal range was found to be 24°C to 39°C. We also present a novel TAC design to demonstrate that one XOR gate of a low-cost Artix-7 FPGA and a simple low-cost circuitry can detect a phase difference as low as 18 ps. The TAC’s linearity is presented through INL and DNL test results. For every additional channel, our TAC requires only one XOR gate in the FPGA chip and a low complexity circuitry. This allows for multichannel operation and larger area availability for use in other implementations. Performance measurements show our TAC to be highly insensitive to temperature and voltage changes.

Minimum Length Scheduling for Full Duplex Time-Critical Wireless Powered Communication Networks

Radio frequency (RF) energy harvesting is key in attaining perpetual lifetime for time-critical wireless powered communication networks (WPCNs) due to full control on energy transfer, far field region, small and low-cost circuitry. In this paper, we propose a novel minimum length scheduling problem to determine the optimal power control, time allocation and schedule subject to data, energy causality and maximum transmit power constraints in a full-duplex WPCN. We first formulate the problem as a mixed integer non-linear programming problem and conjecture that the problem is NP-hard. As a solution strategy, we demonstrate that the power control and time allocation, and the scheduling problems can be solved separately in the optimal solution. For the power control and time allocation problem, we derive the optimal solution by evaluating Karush-Kuhn-Tucker conditions. For the scheduling, we introduce a penalty function allowing reformulation of the problem as a sum penalty minimization problem. Upon derivation of the optimality conditions based on the characteristics of the penalty function, we propose two polynomial-time heuristic algorithms and a reduced-complexity exact algorithm employing smart pruning techniques. Via extensive simulations, we illustrate that the proposed heuristic schemes outperform the schemes for predetermined transmission order of users and achieve close-to-optimal solutions.

Trust-aware energy-efficient stable clustering approach using fuzzy type-2 Cuckoo search optimization algorithm for wireless sensor networks

With the advancement of communication and sensor technologies, it has become possible to develop low-cost circuitry to sense and transmit the state of surroundings. Wireless networks of such circuitry, namely wireless sensor networks (WSNs), can be used in a multitude of applications like healthcare, intelligent sectors, environmental sensing, and military defense. The crucial problem of WSN is the reliable exchange of data between different sensors and efficient communication with the data collection center. Clustering is the most appropriate approach to prolong the performance parameters of WSN. To overcome the limitations in clustering algorithms such as reduced cluster head (CH) lifetime; an effective CH selection algorithm, optimized routing protocol, and trust management are required to design an effective WSN solution. In this paper, a Cuckoo search optimization algorithm using a fuzzy type-2 logic-based clustering strategy is suggested to extend the level of confidence and hence network lifespan. In intra-cluster communication, a threshold-based data transmission algorithm is used and a multi-hop routing scheme for inter-cluster communication is employed to decrease dissipated energy from CHs far away from BS. Simulation outcomes indicate that the proposed strategy outperforms other communication techniques in the context of the successful elimination of malicious nodes along with energy consumption, stability period, and network lifetime.

A portable standalone wireless electric cell-substrate impedance sensing (ECIS) system for assessing dynamic behavior of mammalian cells

In this study, we have developed a wireless, portable, standalone, and simple electric cell-substrate impedance sensing (ECIS) system to analyze in-depth functional aspects of cellular functions on the surface of a co-planar metal electrode coated on conventional glass substrate using a low-cost circuitry and correlated it with an equivalent electrical circuit (EEC) model. Low-cost circuitry was used for studying the dynamic behavior of the mouse myoblast cells (C2C12) in a culture chamber. Further, the developed ECIS system was connected with 8-bit Arduino UNO microcontroller board for establishing a compact sized measuring unit, which can be placed inside a CO2 incubator to provide proper environmental condition for the biological cells during the entire measuring time. Integrating ZigBee RF module with the 8-bit Arduino UNO microcontroller board provides a wireless communication network. Theoretical calculation of the lumped-elemental electrical parameters associated with cell-electrolyte interface and metal-electrolyte interface was calculated. The calculation was performed by fitting the experimental impedance data to EEC model using least mean square method to determine the dynamic and vital functions of the mammalian cells such as proliferation (in real-time) with a change in intrinsic electrical parameters associated at any particular time point. Impedance measurements and the lumped-elemental electrical parameter were correlated with the respective microscopic images. The developed ECIS system was found to enable measuring of the extent of cellular proliferation over time. The compactness of the developed ECIS system integrated with the ZigBee RF module and the 8-bit Arduino UNO microcontroller board facilitates its utilization even when placed in the CO2 incubator for a prolonged time.

A Versatile Method to Enhance the Operational Current of Air-Stable Organic Gas Sensor for Monitoring of Breath Ammonia in Hemodialysis Patients.

Point-of-care (POC) application for monitoring of breath ammonia (BA) in hemodialysis (HD) patients has emerged as a promising noninvasive health monitoring approach. In this context, many organic gas sensors have been reported for BA detection. However, one of the major challenges for its integration with affordable household POC application is to achieve stable performance for accuracy and high operational current at low voltage for low-cost read-out circuitry. Herein, we exploited the stability of the Donor-Acceptor polymer on the cylindrical nanopore structure to realize the sensors with a high sensitivity and stability. Then, we proposed a double active layer (DL) strategy that exploits an ultrathin layer of Poly(3-hexylthiophene-2,5-diyl) (P3HT) to serve as a work function buffer to enhance the operational current. The DL sensor exhibits a sustainable enhanced operational current of microampere level and a stable sensing response even with the presence of P3HT layer. This effect is carefully examined with different aspects, including vertical composition profile of DL configuration, lifetime testing on different sensing layer, morphological analysis, and the versatility of the DL strategy. Finally, we utilize the DL sensor to conduct a tracing of BA concentration in two HD patients before and after HD, and correlate it with the blood urea nitrogen (BUN) levels. A good correlation coefficient of 0.96 is achieved. Moreover, the feasibility of DL sensor integrated into a low-cost circuitry was also verified. The results demonstrate the potential of this DL strategy to be used to integrate organic sensor for affordable household POC devices.

Low-Temperature Aqueous Route Processed Indium Oxide Thin-Film Transistors by NH3 Plasma-Assisted Treatment

We propose a simple and inexpensive strategy for fabricating aqueous route indium oxide thin-film transistors (In2O3-TFTs) at much lower annealing temperatures ( ${T}_{\text {a}}= 140\,\,^{\circ }\text{C}$ ) using NH3 plasma-assisted treatment (PAT) process to In2O3 film surfaces. During the NH3 PAT, the substrate temperature, plasma power, and gas flow were maintained at 140 °C, 50 W, and 100 sccm, respectively. The effect of a sequence of postannealing and PAT, namely, anneal after plasma (AAP)/anneal before plasma (ABP), was studied in detail. The results show that the NH3 PAT can promote the fracture of −OH, passivate the Vo, and increase the conductivity of In2O3 films at low temperatures. The AAP instead of ABP is a suitable method to realize high-performance low-temperature processed In2O3-TFTs on account of the higher oxidation degree, appropriate N doping, as well as more effectively H doping in AAP sample. The fabricated In2O3-TFTs based on AAP exhibited acceptable electrical performance of ~1.3 cm2/ $\text {V}\cdot \text {s}$ mobility and ~107 on/off current ratio at low temperatures. The novel method for fabricating the In2O3-TFTs opens a way for the development of nontoxic, low-cost, and low-temperature oxide circuitry.

Integrated Light Sensing and Communication for LED Lighting

Solid state lighting is nowadays widely diffused both in residential and office or industrial environment. Ambient light sensing to modulate lamp power is typical too, but sensors inside a lamp are a challenge, due to the high flux of these sources, which easily saturates nearby light detectors. Usually, separate sensing devices must be introduced in the system, thus increasing complexity and cost. In this work, a methodology will be presented, to allow integration of a light sensing device inside a lamp, using low cost circuitry to mitigate interactions between high power light-emitting diode (LED) sources and sensing photodiodes. Moreover, the same circuit allows visual light communication among sources.

Improving the timing accuracy of SiPMs by time‐walk compensation

Timing measurements with silicon photomultipliers (SiPMs) are affected by the major issue of the so-called time-walk effect; this is due to the intrinsic architecture of SiPM devices. A new technique for time-walk compensation in timing measurements with SiPMs is presented and discussed, feasible with a low-complexity and low-cost circuitry and able to improve the timing accuracy. The validity of the presented technique has been experimentally proven with a 3 × 3 mm2 Hamamatsu MPPC, achieving a jitter reduction of a factor 2.85 compared with the case without time-walk compensation. To perform the experimental validation, a discrete-components transimpedance amplifier is developed with large bandwidth and low jitter, specifically designed to read-out and amplify the SiPM signal.

Characterization of Ag-Pd Nanocomposite Paste for Electrochemical Migration Resistance

Direct printing such as inkjet, gravure, and screen printing is an attractive approach for achieving low-cost circuitry in the printed circuit board industry. One of the challenges for direct printing technology, however, is the poor resistance to electrochemical migration (ECM), especially for silver (Ag) which has been widely used in printed electronics. We demonstrate improved resistance to Ag electrochemical migration by adding palladium (Pd) nanoparticles to the Ag nanopaste. Conductive comb-type patterns were fabricated on a bismaleimide-triazine substrate via screen printing. Their ECM characteristics were assessed by water drop test with deionized water. These results showed that the ECM time required for dendritic growth from cathode to anode to cause short-circuit failure was affected by the Pd content and applied voltages: the ECM time of Ag-15wt.% Pd nanopaste was nearly threefold that of Ag nanopaste, and the ECM time decreased by 94.22%, on average, while the applied voltage increased from 3 V to 9 V.

A novel variable frequency modulation technique to improve light-load efficiency for multiphase synchronous rectified VRM

A novel variable frequency modulation technique for multiphase synchronous rectified voltage regulator module (VRM) is proposed in this paper. The proposed technique provides zero voltage switching (ZVS) for high-side and low-side power switches under both light- and heavy-load conditions, thereby increasing the efficiency as compared to the conventional approach. The dependency of switching frequency on the load condition for the proposed modulation technique and the related conduction loss are analyzed. It will be shown that the frequency increases for light-load condition in order to retain ZVS and decrease the conduction loss. Although the switching loss will slightly increase due to the increase of switching frequency, the analysis and experimental results will show that the contribution of frequency increasing can cover this additional loss. Experimental results derived from a single-phase and an eight-phase synchronous rectified VRM show that the proposed modulation technique is superior to the conventional one and compared to conventional constant switching frequency techniques with 250 and 550thinspacekHz, the efficiency can be increased up to 17 and 5% for single-phase VRM and 8 and 4% for eight-phase VRM under various load conditions. Even an off-the-shelf controller with an additional simple and cheap control circuit comprising one switch, two operational amplifiers and several resistors is used to realize the proposed technique, that is, a very low cost and small circuitry is attached to gain the significant benefit. Copyright © 2011 John Wiley & Sons, Ltd.

Printed, Sub-3V Digital Circuits on Plastic from Aqueous Carbon Nanotube Inks

Printing electronic components on plastic foils with functional liquid inks is an attractive approach for achieving flexible and low-cost circuitry for applications such as bendable displays and large-area sensors. The challenges for printed electronics, however, include characteristically slow switching frequencies and associated high supply voltages, which together impede widespread application. Combining printable high-capacitance dielectrics with printable high-mobility semiconductors could potentially solve these problems. Here we demonstrate fast, flexible digital circuits based on semiconducting carbon nanotube (CNT) networks and high-capacitance ion gel gate dielectrics, which were patterned by jet printing of liquid inks. Ion gel-gated CNT thin-film transistors (TFTs) with 50 microm channel lengths display ambipolar transport with electron and hole mobilities >20 cm(2)/V.s; these devices form the basis of printed inverters, NAND gates, and ring oscillators on both polyimide and SiO(2) substrates. Five-stage ring oscillators achieve frequencies >2 kHz at supply voltages of 2.5 V, corresponding to stage delay times of 50 micros. This performance represents a substantial improvement for printed circuitry fabricated from functional liquid inks.

Flexible embedded circuitry: A novel process for high density, cost effective electronics

Flexible electronics are starting to emerge with all-printed but also hybrid cost effective, smart electronic products that will find a wide range of applications in large quantities in our society. Such products have to be built on low cost substrate materials like PEN or PET foils. Because of the low thermal stability and limited chemical resistance of these foils, established interconnection technologies are not suitable. The current paper describes a novel technology for making electronic circuitry which does not need incompatible thermal and chemical processes during fabrication. The technology called ‘embedded circuitry’ uses laser ablation to write the circuitry patterns in the flexible foils. These patterns are subsequently filled with conductive pastes using mask-less squeegee filling techniques. Conducting lines in flexible PEN foil with widths down to 10 μm, line gaps down to 10 μm and resistances down to 0.1 Ω/mm are demonstrated. Finite element modeling and bending tests revealed good flexibility of this low cost circuitry. Also the circuitry can be directly used for chip attachment through flipchip bonding.

Hardware/Compiler Memory Protection in Sensor Nodes

With reference to sensor node architectures, we consider the problem of supporting forms of memory protection through a hardware/compiler approach that takes advantage of a low-cost protection circuitry inside the microcontroller, interposed between the processor and the storage devices. Our design effort complies with the stringent limitations existing in these architectures in terms of hardware complexity, available storage and energy consumption. Rather that precluding deliberately harmful programs from producing their effects, our solution is aimed at limiting the spread of programming errors outside the memory scope of the running program. The discussion evaluates the resulting protection environment from a number of salient viewpoints that include the implementation of common protection paradigms, efficiency in the distribution and revocation of access privileges, and the lack of a privileged (kernel) mode.

Acoustic wave touch actuated switch

An acoustic wave switch (12) includes a substrate (14) with an acoustic wave cavity (20) formed therein such that the mass per unit area of the acoustic cavity is greater than the mass per unit area of the substrate adjacent the cavity. A transducer (26) is mounted on the acoustic cavity for generating an acoustic wave that is substantially trapped in the cavity. A touch on the touch surface (28) of the acoustic wave cavity (20) absorbs acoustic wave energy and produces a detectable change in the impedance of the transducer (26). The acoustic wave switch (12) has a high Q so as to enable a touch to be detected by extremely simple, low-cost circuitry. The acoustic wave switch of the present invention is rugged, explosion proof, operates in the presence of liquids and other contaminants, has a low power consumption and can be incorporated and integrally formed in a wall of a housing for a device.

A Low-Cost Driving Circuitry for Permittivity and Moisture Measurement Systems

The implementation of a low-cost driving electronics for a permittivity measurement system employing resonant microwave sensors is presented in this paper The complete driving electronics needed to perform scalar measurements is described; and its components are illustrated and characterized. The measurement results and accuracy have been compared with commercial devices, showing similar performances

Control Sensor Linearization Using Artificial Neural Networks

Traditionally, the issues of cost, size, and weight of artificial neural network implementations have not been the primary concern of researchers. These issues are important in many applications such as those required in space travel, high-volume commercial products, or products with size limitations. In this paper, we discuss methods to improve the characteristics of control sensors using compact and low-cost circuitry. Our objective is to extend the linear region of operation of a nonlinear sensor using artificial neural networks. An analog circuit approach was investigated for high-speed applications and a microcontroller approach for low-speed applications. The methods are applied to the design of a discrete-component phase-locked loop. Both approaches resulted in doubling the sensor‘s linear range.