The Electronic Smell of the Orchard Fruit

Assessing fruit maturity at the end of the season is a hard task for fruit growers. This task is either made by visual inspection – which is tedious and time consuming - or using destructive procedures for measuring biophysical properties of the fruits, such as the sugar content. An alternative to measure the ripeness of fruits is measuring the volatile organic compounds emitted by the fruits. An important compound produced by the fruits in this stage is ethylene (C2H4). The recent advances in electro chemical semiconductors have enabled the rapid growth of electronic noses technologies and applications. Nevertheless, the research reported where its characteristics and limitations are explored only addresses experiments in controlled and indoor settings.Therefore, many questions remain regarding the electronic noses applicability in outdoor environments. This work presents preliminary evidences that there are good chances that ethylene can be detected outdoors via an electronic nose placed within an orchard field. The results presented are measurements acquired in a Conference pear (Pyruscommunis) orchard in September 2017. The measurements where acquired on several points within the field, and the maximum ethylene detection shows an increase of 10% over 400 seconds. These results were contrasted with a theoretical study where gas dispersion patterns can be appreciated when subject to the wind speeds recorded in the field. The simulation results indicated a good correlation between the practical and the theoretical simulation results. To the best of our knowledge this work is the first to report results from measurements using electronic noses in a non-controlled environment, and detecting spatial-temporal variability of natural gas sources

PENGEMBANGAN SENSOR pH BERBASIS BACTERIAL CELLULOSE (Acetobacter xylinum) DAN NANOPARTIKEL EMAS (Au Nanostars) SEBAGAI DETEKTOR KEASAMAN SUSU

Saat ini, perkembangan teknologi yang menuju teknologi smart sensor terus berkembang pesat. Biosensor muncul sebagai alat analisis yang sangat efisien untuk pengukuran resolusi tinggi. Kebutuhan akan metode analisis yang cepat, akurat, efektif, efisien dan mudah terus meningkat. Dalam penelitian ini, pengukuran analitis menggunakan potentiostat. Metode Cyclic Voltametry (CV) berbasis biosensor ini diharapkan dapat mengukur keasaman susu lebih cepat, akurat dengan proses fabrikasi sederhana. Penelitian ini dibagi menjadi 3 tahap yaitu penelitian pendahuluan, penelitian utama dan penelitian lebih lanjutan. Penelitian pendahuluan yang dilakukan adalah untuk mengetahui dampak paparan sinar UV pada hidrofilisitas ITO. Selain itu, penelitian pendahuluan ini bertujuan untuk menentukan karakteristik ITO sebelum dan sesudah pemaparan sinar UV. Penelitian utama yang dilakukan adalah untuk mengetahui pengaruh waktu pertumbuhan bacterial cellulose (BC) terhadap karakter morfologi dan kristalinitas permukaan elektroda. Penelitian lebih lanjut dilakukan untuk menentukan respon pH. Hasil penelitian ini menunjukkan bahwa durasi pertumbuhan selulosa BC mempengaruhi kinerja elektroda yang dimodifikasi dan sifat elektrokimia yang berkaitan dengan permukaan aktif elektro. Struktur biosintesis selanjutnya diterapkan untuk sensor pH melalui analisis CV dan digunakan untuk deteksi keasaman dalam sampel susu. Sensor fabrikasi dipertimbangkan untuk memiliki potensi sebagai platform berbiaya rendah dan mudah dibuat untuk penyaringan kualitas susu. Kata kunci : bacterial cellulose (BC), indium tin oxide, Au Nanostars, Cyclic Voltametry (CV), kualitas susu

Implementation of Sensors and Artificial Intelligence for Environmental Hazards Assessment in Urban, Agriculture and Forestry Systems

The implementation of artificial intelligence (AI), together with robotics, sensors, sensor networks, Internet of Things (IoT), and machine/deep learning modeling, has reached the forefront of research activities, moving towards the goal of increasing the efficiency in a multitude of applications and purposes related to environmental sciences. The development and deployment of AI tools requires specific considerations, approaches, and methodologies for their effective and accurate applications. This Special Issue focused on the applications of AI to environmental systems related to hazard assessment in urban, agriculture, and forestry areas

Food Recognition and Ingredient Detection Using Electrical Impedance Spectroscopy With Deep Learning Techniques to Facilitate Human-food Interactions

Food is a vital component of our everyday lives closely related to our health, well-being, and human behavior. The recent advancements of Spatial Computing technologies, particularly in Human-Food interactive (HFI) technologies have enabled novel eating and drinking experiences, including digital dietary assessments, augmented flavors, and virtual and augmented dining experiences. When designing novel HFI technologies, it is essential to recognize different food and beverages and their internal attributes (i.e., food sensing), such as volume and ingredients. As a result, contemporary research employs image analysis techniques to identify food items, notably in digital dietary assessments. These techniques, often combined with AI algorithms, analyze digital food images to extract various information about food items and quantities. However, these visual food analyzing methods are ineffective when: 1) identifying food’s internal attributes, 2) discriminating visually similar food and beverages, and 3) seamlessly integrating with people’s natural interactions while consuming food (e.g., automatically detecting the food when using a spoon to eat). This thesis presents a novel approach to digitally recognize beverages and their attributes, an essential step towards facilitating novel human-food interactions. The proposed technology has an electrical impedance measurement unit and a recognition method based on deep learning techniques. The electrical impedance measurement unit consists of the following components: 1) a 3D printed module with electrodes that can be attached to a paper cup, 2) an impedance analyzer to perform Electrical Impedance Spectroscopy (EIS) across two electrodes to acquire measurements such as a beverage’s real part of impedances, imaginary part of impedances, phase angles, and 3) a control module to configure the impedance analyzer and send measurements to a computer that has the deep learning framework to conduct the analysis. Two types of multi-task learning models (hard parameter sharing multi-task network and multi-task network cascade) and their variations (with principal component analysis and different combinations of features) were employed to develop a proof-of-concept prototype to recognize eight different beverage types with various volume levels and sugar concentrations: two types of black tea (LiptonTM and TwiningsTM English-Breakfast), two types of coffee (StarbucksTM dark roasted and medium roasted), and four types of soda (regular and diet coca-cola, and regular and diet Pepsi). Measurements were acquired from these beverages while changing volume levels and sugar concentrations to construct training and test datasets. Both types of networks were trained using the training dataset while validated with the test dataset. Results show that the multi-task network cascades outperformed the hard parameter sharing multi-task networks in discriminating against a limited number of drinks (accuracy = 96.32%), volumes (root mean square error = 13.74ml), and sugar content (root mean square error = 7.99gdm3). Future work will extend this approach to include additional beverage types and their attributes to improve the robustness and performance of the system and develop a methodology to recognize solid foods with their attributes. The findings of this thesis will contribute to enable a new avenue for human-food interactive technology developments, such as automatic food journaling, virtual flavors, and wearable devices for non-invasive quality assessment

Review of low-cost sensors for the ambient air monitoring of benzene and other volatile organic compounds

This report presents a literature review of the state of the art of sensor based monitoring of air quality of benzene and other volatile organic compounds. Combined with information provided by stakeholders, manufacturers and literature, the review considered commercially available sensors, including, PID based sensors, semiconductor (resistive gas sensor) and portable on-line measuring devices (sensor arrays). The bibliographic collection includes the following topics: sensor description, field of application in fixed, mobile, indoor and ambient air monitoring, range of concentration levels and limit of detection in air, model descriptions of the phenomena involved in the sensor detection process, gaseous interference selectivity of sensors in complex VOC matrix, validation data in lab experiments and under field conditions.JRC.C.5-Air and Climat

실리콘 기판 위에 효율적으로 집적한 기압 센서와 FET형 가스 센서

학위논문 (박사) -- 서울대학교 대학원 : 공과대학 전기·정보공학부, 2020. 8. 이종호.Sensor technology is becoming increasingly important to improve the quality of human life. Especially, various kinds of sensor technology have become essential due to increasing demand for smart mobile devices, automobiles and household appliances. Furthermore, as many types of sensors are installed on smart devices, it is more important to integrate different sensors in the IoT era. If multiple types of sensors are efficiently integrated with CMOS circuit on a single substrate, the footprint and power consumption could be reduced. Gas sensors are not only for detecting harmful gases, but also for improving indoor air quality and detecting diseases. The conventional resistor-type gas sensors have a simple structure and a simple manufacturing process, but they are large in size and have high power consumption. On the other hand, FET-type gas sensors can be fabricated very small in size and compatibly integrated with CMOS circuits, and they are easy to integrate with other types of sensors. In addition, built-in localized micro-heater can minimize power consumption of the FET-type gas sensors. In this dissertation, barometric pressure sensors and Si FET-type gas sensors are efficiently integrated on the same Si substrate using conventional MOSFET fabrication process. The barometric pressure sensors have built-in temperature sensors to accurately measure the atmospheric pressure according to the ambient temperature. In addition, the FET-type gas sensor has a localized micro-heater capable of heating up to 124 ºC with a power of 4 mW. NO2 gas sensing is successfully achieved with this gas sensor. Air-gap with a depth of 2.5 μm are formed in the Si substrate and used as the cavity for the barometric pressure sensor and as an insulating layer for the FET-type gas sensor. In addition, poly-Si with Boron ion implantation is used as the piezo-resistors of the barometric pressure sensor, the electrode of the temperature sensor, and the FG and micro-heater of the FET-type gas sensor at the same time. In this way, the barometric pressure sensors and the FET-type gas sensors are efficiently integrated using CMOS compatible fabrication process. The barometric pressure sensor has a built-in temperature sensor that can measure ambient temperature and atmospheric pressure at the same time. The measured atmospheric pressure varies with ambient temperature, but with a designed neural network, accurate atmospheric pressure can be obtained with an accuracy of 97.5 %.사물 인터넷 (IoT) 시대를 맞이하여 삶의 질을 개선하기 위한 센서 기술들이 점차 중요해지고 있다. 특히, 각종 스마트 기기들을 비롯한 자동차 및 가전 제품에 대한 센서 기술들이 필수적이 되고 있다. 아울러, 다양한 종류의 센서들의 통합 및 집적 기술이 주목받고 있다. 여러 유형의 센서들을 단일 기판에서 CMOS 회로와 효율적으로 통합하면 전력 소모를 줄일 수 있으며, 제조 단가 또한 낮출 수 있다. 다양한 센서기술 중 가스 센서는 유해 가스 감지뿐만 아니라 실내 공기 질 개선 및 질병 감지에 사용될 것으로 예상된다. 종래의 저항 형 가스 센서는 구조가 간단하며 제조 공정이 단순하지만 크기가 크고 전력 소비가 높은 편이다. 한편, FET 형 가스 센서는 매우 작은 크기로 제작이 가능하며 CMOS 회로와 호환 가능하다. 또한 내장된 마이크로 히터 (Micro-Heater)를 사용하게 되면 FET 형 가스 센서의 전력 소비를 최소화 시킬 수 있다. 본 논문에서는 기압 센서와 Si FET 형 가스 센서를 MOSFET 제조 공정기술을 사용하여 단일 실리콘 (Silicon) 기판에 효율적으로 집적하였다. 제작된 기압 센서는 온도 센서를 내장하고 있어서 주변 온도에 따른 대기압을 정확하게 측정 가능하다. 또한 FET 형 가스 센서는 4 mW의 전력으로 최대 124 ˚C까지 가열 할 수 있는 국부화 된 마이크로 히터를 내장하고 있다. 이 가스 센서로 이산화 질소가스 (NO2)의 농도를 측정하였다. 2.5 μm 깊이의 에어 갭 (Air-gap)을 Si 기판에 형성하고 이 에어 갭은 기압 센서의 공동 (Cavity) 및 FET 형 가스 센서의 절연 층으로 사용하였다. 또한, 붕소(Boron) 이온을 주입한 다결정 실리콘 (Poly-Si)은 기압 센서 및 온도 센서의 전극, FET 형 가스 센서의 플로팅 게이트 (Floating-gate), 그리고 마이크로 히터의 전극으로 동시에 사용하였다. 이러한 방식으로 기압 센서, FET 형 가스센서는 CMOS 호환 제조 공정을 사용하여 효율적으로 단일기판에 집적하였다. 기압 센서는 주변 온도와 대기압을 동시에 측정 할 수 있는 온도 센서를 내장하고 있으며, 주변 온도에 따른 대기압을 신경망을 통하여 97.5 %의 정확도로 측정할 수 있다.Chapter 1. Introduction 1 1.1. Sensor technology 1 1.1.1. Various types of sensors 1 1.1.2. Conventional MEMS sensors 2 1.2. Barometric pressure sensors 5 1.2.1. MEMS barometric pressure sensors 5 1.2.2. Diaphragm of barometric pressure sensors 6 1.2.3. Cavity in barometric pressure sensors 7 1.2.4. Types of barometric pressure sensors 9 1.3. Gas sensors 12 1.3.1. Resistor-type gas sensors 12 1.3.2. FET-type gas sensors 13 1.3.3. Heater and air-gap in gas sensors 17 1.4. Integration of various types of sensors 21 1.5. Purpose of research 22 1.6. Dissertation outline 23 Chapter 2. Device structure and fabrication 24 2.1. Integration of different sensors 24 2.2. Structure of barometric pressure sensors 26 2.2.1. Air pocket of barometric pressure sensors 26 2.2.2. New design of piezo-resistor 28 2.3. Structure of FET-type gas sensors 32 2.3.1. Structure and layout of FET-type gas sensors 32 2.4. Device fabrication 35 2.4.1. Key fabrication process 35 2.4.2. Formation of sensing material on FET-type gas sensors 47 Chapter 3. Device characteristics 49 3.1. Characteristics of barometric pressure sensors 49 3.1.1. Device simulation 49 3.1.2. Measurement setup 56 3.1.3. Measurement results 59 3.2. Characteristics of temperature sensors and micro-heater 63 3.2.1. Temperature sensor and its characteristics 63 3.2.2. Micro-heater of the gas sensors 70 3.3. Characteristics of gas sensors 77 3.3.1. I-V characteristics and nonvolatile functionality of FET-type gas sensors 77 3.3.2. Gas sensing mechanism 79 3.3.3. Gas measurement results 83 3.4. MLP neural network 86 Chapter 4. Conclusion 89 Bibliography 91 Abstract in Korean 100Docto

Selected Papers from the 1st International Electronic Conference on Biosensors (IECB 2020)

The scope of this Special Issue is to collect some of the contributions to the First International Electronic Conference on Biosensors, which was held to bring together well-known experts currently working in biosensor technologies from around the globe, and to provide an online forum for presenting and discussing new results. The world of biosensors is definitively a versatile and universally applicable one, as demonstrated by the wide range of topics which were addressed at the Conference, such as: bioengineered and biomimetic receptors; microfluidics for biosensing; biosensors for emergency situations; nanotechnologies and nanomaterials for biosensors; intra- and extracellular biosensing; and advanced applications in clinical, environmental, food safety, and cultural heritage fields

The 1st International Electronic Conference on Chemical Sensors and Analytical Chemistry

The 1st International Electronic Conference on Chemical Sensors and Analytical Chemistry was held on 1–15 July 2021. The scope of this online conference was to gather experts that are well-known worldwide who are currently working in chemical sensor technologies and to provide an online forum for the presention and discussion of new results. Throughout this event, topics of interest included, but were not limited to, the following: electrochemical devices and sensors; optical chemical sensors; mass-sensitive sensors; materials for chemical sensing; nano- and micro-technologies for sensing; chemical assays and validation; chemical sensor applications; analytical methods; gas sensors and apparatuses; electronic noses; electronic tongues; microfluidic devices; lab-on-a-chip; single-molecule sensing; nanosensors; and medico-diagnostic testing

Research and Technology 1996: Innovation in Time and Space

As the NASA Center responsible for assembly, checkout, servicing, launch, recovery, and operational support of Space Transportation System elements and payloads, the John F. Kennedy Space Center is placing increasing emphasis on its advanced technology development program. This program encompasses the efforts of the Engineering Development Directorate laboratories, most of the KSC operations contractors, academia, and selected commercial industries - all working in a team effort within their own areas of expertise. This edition of the Kennedy Space Center Research and Technology 1996 Annual Report covers efforts of all these contributors to the KSC advanced technology development program, as well as our technology transfer activities