AbstractThe development of thin-film sensors for temperature and wear measurement in machining operations is presented in this work. A functional thin-film system, consisting of an Al2O3 insulation layer, a chromium sensor layer structured by photolithography and an Al2O3 wear-protection and insulation layer, is deposited by physical vapor deposition (PVD) processes onto the surface of cemented carbide cutting inserts. First specimen of the sensors are successfully fabricated and tested in laboratory experiments as well as in machining operations to demonstrate their functionality. These tool-integrated sensors can be used as an in-process monitoring device to determine the temperatures on the rake face at or close to the tool-chip contact area and to measure the progress of the flank-wear land width. The knowledge of these important process parameters opens up the possibility to develop new in-process control mechanisms in order to modify and improve the surface integrity of manufactured components. Thereby, their performance and lifetime can be enhanced.
Abstract
Thin film sensors are used to monitor environmental conditions by measuring the physical parameters. By using thin film technology, the sensors are capable of conducting precise measurements. Moreover, the measurements are stable and dependable. Furthermore, inexpensive sensor devices can be produced. In this paper, thin film technology for the design and fabrication of sensors that are used in various applications is reviewed. Further, the applications of thin film sensors in the fields of biomedical, energy harvesting, optical, and corrosion applications are also presented. From the review, the future research needs and future perspectives are identified and discussed.
Purpose
The present study aims to describe the development of halochromic thin film sensors using mixed indicator dyes for monitoring the spoilage of packed seer fish.
Design/methodology/approach
Thin film was prepared using renewable polysaccharide incorporated with mixed indicator dyes. The thin film was characterized using ultraviolet visible and Fourier transform-infrared spectroscopy. The characteristics of the thin film were studied by analyzing the CIELAB and Red Green Blue values and biodegradability. The thin films were evaluated for real-time monitoring of the spoilage of packed seer fish.
Findings
The thin film sensors were found to exhibit excellent halochromism. The color changes were visible and distinguishable. The sensors responded efficiently for real-time monitoring of spoilage of fish by showing unique color changes.
Originality/value
This study provides promising mixed indicator that exhibits different colors in the alkaline pH. Also the present study reveals a potential combination of materials for preparation of halochromic sensors that can be used for monitoring the spoilage of packed seer fish in real time.
Fabrication of thin film sensors by spin coating using sol-gel LaCrO3 Perovskite material modified with transition metals for sensing environmental pollutants, greenhouse gases and relative humidity
