No abstract

This paper shows that we can print on paper simple high-frequency electronic devices such as resistances, capacitances or inductances, with values that can be changed in a controllable manner by an applied dc voltage. This tunability is achieved with the help of an ink containing functionalized carbon nanotubes and water. After the water is evaporated from the paper, the nanotubes remain steadily imprinted on paper, showing a semiconducting behavior and tunable electrical properties.

Electrical detection of biotic materials and their properties is always crucial in Biomedical Engineering. It emphasizes elaborate analysis of a certain disease diagnosis using electrical means which includes the study of electrical properties followed by detection, identification, and quantification of biotic entities. Proper and early detection of cells, which can be normal or cancerous, holds never-ending demand. This review emphasizes the electrical characterization methods in modeling and classification of cell properties. Moreover, standard methods have been highlighted and discussed to yield performance analysis. This study suggests that techniques presented for single-cell analysis (SCA) are always precise and hold great scope compared to those for cell mixture. SCA plays a promising role in disease diagnosis and treatment planning, as it not only detects the cells but also helps in identification. Distinct electrical-based cell detection techniques are highlighted, along with the pros and cons of various SCA devices. The content, in terms of methodologies and available techniques, of this review paper is useful to attract researchers working in this area.

Here we identify and quantitate two similar viruses, human and feline immunodeficiency viruses (HIV and FIV), suspended in a liquid medium without labeling, using a semiconductor technique. The virus count was estimated by calculating the impurities inside a defined volume by observing the change in electrical parameters. Empirically, the virus count was similar to the absolute value of the ratio of the change of the virus suspension dopant concentration relative to the mock dopant over the change in virus suspension Debye volume relative to mock Debye volume. The virus type was identified by constructing a concentration-mobility relationship which is unique for each kind of virus, allowing for a fast (within minutes) and label-free virus quantification and identification. For validation, the HIV and FIV virus preparations were further quantified by a biochemical technique and the results obtained by both approaches corroborated well. We further demonstrate that the electrical technique could be applied to accurately measure and characterize silica nanoparticles that resemble the virus particles in size. Based on these results, we anticipate our present approach to be a starting point towards establishing the foundation for label-free electrical-based identification and quantification of an unlimited number of viruses and other nano-sized particles.

No abstract

No abstract

the monitoring of vital signs plays a key role in the diagnosis of several diseases. piezoelectric sensors have been utilized to collect a corresponding representative signal from the chest surface. the subject typically needs to hold his or her breath to eliminate the respiration effect. This work further contributes to the extraction of the corresponding representative vital signs directly from the measured respiration signal. The contraction and expansion of the heart muscles, as well as the respiration activities, will induce a mechanical vibration across the chest wall. The induced vibration is then captured by the piezoelectric sensor placed at the chest surface, which produces an electrical output voltage signal conformally mapped with the respiration-cardiac activities. During breathing, the measured voltage signal is composed of the cardiac cycle activities modulated along with the respiratory cycle activity. A representative model that incorporates the cardiac and respiratory activities is developed and adopted. The piezoelectric and the convolution theories along with Fourier transformation are applied to extract the corresponding cardiac activity signal from the respiration signal. All the results were validated step by step by a conventional apparatus, with good agreement observed. Monitoring vital signs is essential for daily health and medical diagnosis 1. Vital signs, such as electrocardiogram (ECG) measurements, heart rate 2 , respiration rate 3 , systolic pressure (SP), and diastolic pressure (DP) 4 , along with pressure pulse play an important role in determining the state of health of a subject 5. Various methods and systems have recently been developed to monitor such vital signs 6-12. These vital signs are extracted from the acquired signals that enable more effective safeguarding of health by allowing for the early detection of any disease or abnormality 13-15. Researchers have recently focused on developing a remote non-contact sensing system having the ability to perform accurate long-term continuous monitoring of human vital signs. Measuring vital signs (such as respiration rates, blood pressure, and heart rates) continuously and remotely without touching the patients can be an invaluable tool for physicians, as it can be used to make life-and-death decisions rapidly and make better decisions when long-term patient data are available 16. The systems used to monitor vital signs may prevent diseases and enhance quality of life, thus reducing the costs of health care 17. Noninvasive vital sign monitoring, which includes measurement of pulse oximetry 18 , capnography, blood pressure (BP) measurement, and the standard five-lead electrocardiogram 19 , has been used for patients who are in the intensive care unit 20 and in the operating room. A stepped frequency continuous wave (SFCW) radar is also used to measure the heart rate and respiration by transmitting high average power pulses with long duration and narrow bandwidth, then a signal-processing algorithm based on the state space method is...

This letter reports low-field wide-tunable interdigitated barium strontium titanate (BST) capacitors. The capacitors consisting of BST thin film dielectric, silicon substrate, and gold metallization have been fabricated. The capacitance exhibits 0.2 pF at zero-bias and shows a tunability of 63% with an applied electric field of 1.4 V m. This corresponds to a 3.5 m electrode gap width and a 5 V dc bias. Microwave measurements reveal a zero bias film quality of 50 around 30 GHz.