Carlos Omar González-Morán

Opacity Sensor Based on Photovoltaic Effect of Ferroelectric PLZT Ceramic With Pt Wire Implant

This work reports the formation of a ferroelectric poled bulk ceramic structure as opacity sensor (OPS) and the improved photovoltaic output of the lead lanthanum zirconate titanate (PLZT) employed. This ceramic was implanted during its fabrication with a platinum wire (Pt-wire) which works as an internal electrode. Photovoltaic current have been measured in PLZT with Pt-wire under chopped LASER beam illumination. This photovoltaic current was measured on the upper face of a sensor in order to obtain a characterization curve. Different thin materials were put on the OPS in order to determine its opacity according to their thickness and viscosity. Opacity is a condition in which a material partially or completely impedes the passage of light beam. The results indicated that the photovoltaic current response was less than 700 pA at 160 mW/cm2 maximum power of illumination; 2-D scans were obtained from fruit tissues, vegetal oils and thin materials at 160 mW/cm2 of illumination in order to get a representation of opacity images.

A Piezoelectric Plethysmograph Sensor Based on a Pt Wire Implanted Lead Lanthanum Zirconate Titanate Bulk Ceramic

This work reports on the development of a Lead Lanthanum Zirconate Titanate (PLZT) bulk ferroelectric poled ceramic structure as a Piezoelectric Plethysmograph (PZPG) sensor. The ceramic was implanted during its fabrication with a platinum (Pt) wire which works as an internal electrode. The ceramic was then submitted to an experimental setup in order to validate and determine the Pt-wire mechanical effects. This PZPG sensor was also mounted on a finger splint in order to measure the blood flow that results from the pulsations of blood occurring with each heartbeat. Fingertip pulses were recorded jointly with an ECG signal from a 25 year old male to compare the time shift; the PZPG sensor guarantees the electrical isolation of the patient. The proposed PZPG has several advantages: it can be adjusted for fingertip measurements, but it can easily be extended by means of spare bands, therefore making possible PZPG measurements from different body locations, e.g., forehead, forearm, knee, neck, etc.

Developed and Experimental Evidence of a Ceramic-Controlled Piezoelectric Bulk Implanted with Pt Wire Based on PLZT

This work reports on the formation of a Lead Lanthanum Zirconate Titanate bulk ferroelectric poled ceramic structure as ceramic-controlled piezoelectric, this ceramic was implanted during its fabrication with platinum wire that operates as an internal electrode. The CCP was submitted in two experimental setups to validate and determine the Pt-wire optical and mechanical effects. Dielectric constant was determined on ceramic-controlled piezoelectric with and without Pt wire.

Development of Poly(vinylidene flouride) Polymer Applied in Force Sensors for Gait Analysis in Wistar Mice of Physiology Research Laboratory

A group of force sensors was designed and manufactured. These are based on piezoelectric poly(vinylidene diflouride) (PVDF) films. These sensors will help evaluate the revascularization process in Wistar mouse legs. The sensors were calibrated from 0.0 to 14.4 g and had an uncertainty of ±7.5 mN.

Developed and applications of a novel ceramic-controlled piezoelectric due to an implant of Pt-wire into the body of single disk of BaTiO3 ceramic

A Platinum wire was implanted into the single disk bulk of Barium Titanate (BaTiO3) named ceramiccontrolled piezoelectric (CCP). In addition, some typical applications of the CCP in the fields of optical, acoustical, mechanical, thermal and electrical, were proposed as demonstrative experiments in this work. This novel CCP offers a opportunity to develop new sensors, the circumstances are right for working in diverse fields of applied research.

Ceramic-Controlled Piezoelectric Bulk Implanted with Pt Wire Based on BaTiO3 (Optical Microscopy, SEM, EDS) and PLZT (Optical Bi-dimensional Characterization)

This paper describes the formation of poled bulk ferroelectric ceramics made of Lead Lanthanum Zirconate Titanate (PLZT) and Barium Titanate (BaTiO3). These ceramics were implanted during their fabrication with a platinum wire (Pt-wire), which worked as an internal electrode. This internal electrode was verified by means of optical microscopy, SEM, and EDS of the Barium Titanate (BaTiO3) ceramic to determine some chemical reaction. The analysis was checked only in BaTiO3 because it is the most common ferroelectric ceramic. Finally, the photovoltaic signal was measured in PLZT with the Pt-wire in a bi-dimensional experimental setup, with a resolution of 50 μm.

Cardiac skin micropulsation acquisition system based on pressure sensor made of PLZT with implant

From the development of a disc of ceramics made with lead lanthanum zirconate (PLZT) and implanted with platinum wire, important applications became. In this case already the successful functionality of the detection of the cardiac pulse with this ceramics has been reported; nevertheless the present work shows the development of this sensor with a system of data acquisition that is very important for the signal records, analysis and comparison of cardiac pulses and electrical registry of the heart. The system of acquisition of pulse shows in a computer screen a friendly atmosphere to us that can be adapted to diverse situations of measurement.

Controlled piezoelectric ceramic as cardiac pulse sensor

Using Pb1-xLax (ZR1-yTiy) 01-x/4O3 with x = 0.09 y = 0.65 (PLZT) denoted as (9/65/35) as base material and introducing a transverse platinum wire we developed a ceramic piezoelectric sensor whose main characteristic allows the ballistic measurement. The sensor dimensions are: diameter 1 cm, thickness 2 mm, and shows good characteristics as a sensor of cardiac pulse. Performing an assembly which allows us to get a signal from mechanical contact with the index finger and from the ear lobe. The signal obtained was compared to the ECG signal has important features for further analysis, the signal obtained was measured between the implant and the Pt side in pico amperes, obtaining good results. Finally, the heart pulse sensor can be placed in many living organisms and allows observation of small mechanical activity without contaminating the patient or biological sample.

Controlled piezoelectric ceramic as tissue opacity sensor, using photovoltaic effect

Made with Pb1-xLax (ZR1-yTiy) 01-x/4O3 with x = 0.09 y = 0.65 (PLZT) denoted as (9/65/35) and implanted with platinum the transparent ceramic sensor is 1cm in diameter and 2 mm thick. It shows good characteristics as a sensor for opacity of biological tissue (SOBT). When illuminating the front of SOBT with pulsed laser light at 650 nm with a maximum illumination power of 160 mW at a frequency of 3 Hz and a distance of 1cm, and due to the photovoltaic effect a signal current of the order of pico amperes can be measured between the implant and the Pt side. When one places on the front face different materials (such as glass, polyethylene, acetate, carbon paper, epicarp of plum or apple) the opacity can be measured and good results obtained. Finally, the data shows SOBT repeatable with good characteristics. It is a tiny sensor and can record the opacity of most translucent material without contaminating the sample.

Synthesis and Characterization of Zn-Nix Advanced Alloys Prepared by Mechanical Milling and Sintering at Solid-State Process

Mechanical ball milling assisted by sintering in the solid state was used in this research to produce the Zn-Nix system alloy. The derivative powder compositions of Zn-Nix (x = 0, 5, 10, 15, and 20 wt.%) were obtained to study the Ni effects on the microstructural and mechanical properties. It is worth remarking that conventional methods are not appropriate for the manufacture of the Zn-Nix system alloy. The morphological structure and phases were examined by optical microscopy, X-ray diffraction, and SEM/EDS elemental mapping, whereas the mechanical behavior was accomplished by means of a diamond indentation print (Hardness Vickers). The results showed that the intermetallic γ-ZnNi phase did not form during milling time (<4 h); it appears after the sintering process, which is associated with atomic diffusion mechanism through grain boundary at the minimum interfacial energy (ΔG256°C = −13.83 kJ·mol−1). The powder Zn-Ni10 was found to have better properties. Semispherical coarser particles were seen into the metal matrix (Zn δ-hcp structure) as segregates; however, each particle contains an intermetallic compound Zn-Ni that encloses the Ni (α-fcc structure) pure phase. The Ni-α phase was then transformed into a γ-ZnNi intermetallic compound which shifts to higher values of mechanical hardness from about 60 HV to 400 HV units.