https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/j.molonc.2008.04.001

Imaging and cancer: A review

Xin Zhou,†,‡ Songyi Lee,† Zhaochao Xu,* and Juyoung Yoon*,† †Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 120-750, Republic of Korea ‡Research Center for Chemical Biology, Department of Chemistry, Yanbian University, Yanjii 133002, People’s Republic of China Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Shahekou, Dalian, Liaoning, People’s Republic of China

Recent Progress on the Development of Chemosensors for Gases.

流体力学用語集 非線形音響学(Nonlinear acoustics)

Micro- and nano-sensors lie at the heart of critical innovation in fields ranging from medical to environmental sciences. In recent years, there has been a significant improvement in sensor design along with the advances in micro- and nano-fabrication technology and the use of newly designed materials, leading to the development of high-performance gas sensors. Advanced micro- and nano-fabrication technology enables miniaturization of these sensors into micro-sized gas sensor arrays while maintaining the sensing performance. These capabilities facilitate the development of miniaturized integrated gas sensor arrays that enhance both sensor sensitivity and selectivity towards various analytes. In the past, several micro- and nano-gas sensors have been proposed and investigated where each type of sensor exhibits various advantages and limitations in sensing resolution, operating power, response, and recovery time. This paper presents an overview of the recent progress made in a wide range of gas-sensing technology. The sensing functionalizing materials, the advanced micro-machining fabrication methods, as well as their constraints on the sensor design, are discussed. The sensors’ working mechanisms and their structures and configurations are reviewed. Finally, the future development outlook and the potential applications made feasible by each category of the sensors are discussed.

Advanced Micro- and Nano-Gas Sensor Technology: A Review

Capacitive micromachined ultrasonic transducers (CMUTs) have been subject to extensive research for the last two decades. Although they were initially developed for air-coupled applications, today their main application space is medical imaging and therapy. This paper first presents a brief description of CMUTs, their basic structure and operating principles. Our progression of developing several generations of fabrication processes is discussed with an emphasis on the advantages and disadvantages of each process. Monolithic and hybrid approaches for integrating CMUTs with supporting integrated circuits are surveyed. Several prototype transducer arrays with integrated front-end electronic circuits we developed and their use for 2D and 3D, anatomical and functional imaging, and ablative therapies are described. The presented results prove the CMUT as a micro-electro-mechanical systems technology for many medical diagnostic and therapeutic applications.

/pdf/capacitive-micromachined-ultrasonic-transducers-for-medical-1c8bymjvrh.pdf

Capacitive micromachined ultrasonic transducers for medical imaging and therapy

Zur Demodulation eines amplitudenmodulierten Signals sind zwei Kondensatoren (C1, C2) vorgesehen, denen ein mit einer Diode (D1) gleichgerichtetes Signal mit einer Spannung (U1) zufuhrbar ist. Die Halbwellen dieses Signals werden mit einem Schalter (S3) abwechselnd zur Aufladung des ersten oder zweiten Kondensators benutzt. Mit Schaltern (S1, S2) werden die Kondensatoren (C1, C2) entladen. Ein Vergleich der in den Kondensatoren (C1, C2) gespeicherten Amplitudenwerte aufeinanderfolgender Halbwellen in einer Auswerteeinheit (AE) ermoglicht eine einfache, mit wenigen Bauelementen realisierbare und prazise Demodulation, welche bei sehr hohen Frequenzen moglich ist.

Demodulationschaltung und Demodulationsverfahren

Piezoelectrets (or ferroelectrets) are polarized cellular polymers exhibiting outstanding piezoelectric activity. Recently, a new manufacturing route has been introduced by combining 3-D-printed elastomeric soft grids and bulk fluorinated ethylene propylene (FEP) thin films to build an artificial ferroelectret sandwich exhibiting outstanding <inline-formula> <tex-math notation="LaTeX">${d} _{{33}}$ </tex-math></inline-formula> coefficients. In this work, a similar approach is taken, however, replacing the environmentally harmful fluorinated polymer FEP by eco-friendly polylactic acid (PLA). The goal of this study is thereby threefold: 1) to investigate the temporal charge stability of PLA films charged at 25 °C and 80 °C, respectively; 2) to determine the stability of the piezoelectric activity when assembled as ferroelectret; and 3) to study the applicability of this easy assembled eco-friendly sensors for force myography (FMG). The surface potential of the PLA films was recorded over 180 days and showed promising stability. Because of the high flexibility of the spacer material, a large piezoelectric <inline-formula> <tex-math notation="LaTeX">${d} _{{33}}$ </tex-math></inline-formula> coefficient of up to 2850pC/N was recorded directly after charging and stabilized at about 1500pC/N after <inline-formula> <tex-math notation="LaTeX">$\approx 50$ </tex-math></inline-formula> days under ambient environmental conditions. The FMG was conducted using four similar ferroelectrets placed on a human forearm. The generated signal shapes and magnitudes of the sensors can be clearly distinguished from each other using simple machine learning algorithms known as support vector machine (SVM) with a classification accuracy (CA) of 89.5%. This work can be regarded as a milestone for these sensors to be accepted in the field of human–machine interfaces (HMIs) as an eco-friendly alternative to the conventional piezoelectric sensors.

Eco-Friendly High-Sensitive Piezoelectrets for Force Myography

For quality control and functionality testing, Contact Normal Forces F N need to be measured in multi contact point connectors like MCON 8 with the least mating cycles possible. This article is about the design and the characterization of a 4-channel gage. Each channel gage consists of a metal transducer with a metal foil strain gage. The forces range from 2 N to 8 N. The gage is built-up in a modular way, connected to a data acquisition (DAQ), and its measurement system analysis MSA capability has been proven. The sensor will be implemented into the in-production quality control of the MCON 8 connector and will provide data to a global Digital Quality Inspection Plan (DQIP)-linked F N database.

Force sensor with increased local resolution for electronic Contact Normal Force measurement in electrical connectors

Acoustic waveguides offer grating lobe-free beam-forming for air-coupled phased arrays. Due to the separation of the transducers aperture and the radiating aperture, the output of the phased arrays can be freely designed independent of the transducers geometry. However, since the output ports of the waveguide are open they can be easily clogged due to liquids, dirt or dust. In previous work, we investigated multiple solutions for this issue and concluded that there is a compromise between water resistance and minimal acoustic losses. In this work we reduced the losses of thin films to combine low insertion losses (IL) with high protection classes of up to IP 68. By introducing thermo-viscous effects to the waveguide, the resonance frequencies of the transducer and the film can be combined. In addition, the position of the film inside the waveguide was optimized and we switched from low density polyethylene (LDPE) to polylactic acid (PLA) as a film material. As a result, we were able to reduce the IL to 0.4 dB±1 dB while remaining the same water resistance from previous work.

Optimization of thin film protection for waveguided ultrasonic phased arrays

Additive manufacturing technologies allow the fabrication of complex and bioinspired shapes of magneto-responsive materials which have various applications in soft robotics. The fabrication of these composites with gradients in mechanical properties offers new possibilities in the field of magneto-active materials. However, this usually requires complex multi-material printing steps. Here, a single-step laser powder bed fusion (LPBF) process is presented that enables the local adjustement of the mechanical stiffness of a magneto-active composite. The application of locally different laser parameters, during the processing of a composite consisting of thermoplastic polyurethane and atomized magnetic powder based on hard magnetic Nd-Fe-B, can change the stiffness of the composite from 2 to 22 MPa. Different magneto-responsive actuators, with locally adjusted stiffnesses, are fabricated and their magnetic properties are investigated. The enhanced response of actuators with locally adjusted mechanical properties is demonstrated in comparison to homogenous actuators with the same geometry. As demonstraction for a biomedical application, a locally adjusted stent which can meet requirements for geometry and local stiffness speficially for a individual anatomy and disease is demonstrated. Further implementation of the proposed process in these areas will help to make progress in the integration of soft and rigid components in various applications such as soft robotics and locomotion assistance devices. The presented method shows a roadmap to create functionally graded materials with LPBF, not only in magneto-active materials, but also in various other structural and functional materials.

Mario Kupnik

Papers

Demodulationschaltung und Demodulationsverfahren

Eco-Friendly High-Sensitive Piezoelectrets for Force Myography

Force sensor with increased local resolution for electronic Contact Normal Force measurement in electrical connectors

Optimization of thin film protection for waveguided ultrasonic phased arrays

Local stiffness tailoring of magneto-active composites produced by laser powder bed fusion