Recent progress in three-dimensional flexible physical sensors

Three-dimensional(3D)functional systems are of rapidly growing interest over the past decade,from the perspective of both the fundamental and applied research.In particular,tremendous efforts have been devoted to the developments of 3D flexible,physical sensors,partly because of their substantial advantages over planar counterparts in many specific performances.In this review,we summarize recent advances in diverse categories of 3D flexible physical sensors,covering the photoelectric,mechanical,temperature,magnetic,and other physical sensors.This review mainly focuses on their design strategies,working principles and applications.Finally,we offer an outlook on the future developments,and provide perspectives on the remaining challenges and opportunities in this area.

PEDOT:PSS:From conductive polymers to sensors

PEDOT:PSS conductive polymers have received tremendous attention over the last two decades owing to their high conductivity,ease of processing,and biocompatibility.As a flexible versatile material,PEDOT:PSS can be developed into various forms and has had a significant impact on emerging sensing applications.This review covers the development of PEDOT:PSS from material to physical sensors.We focus on the morphology of PEDOT:PSS in the forms of aqueous dispersions,solid films,and hydrogels.Manufacturing processes are summarized,including coating,printing,and lithography,and there is particular emphasis on nanoimprinting lithography that enables the production of PEDOT:PSS nanowires with superior sensing performance.Applications to various physical sensors,for humidity,temperature,pressure,and strain,are demonstrated.Finally,we discuss the challenges and propose new directions for the development of PEDOT:PSS.

Modeling random telegraph signal noise in CMOS image sensor under low light based on binomial distribution

The random telegraph signal noise in the pixel source follower MOSFET is the principle component of the noise in the CMOS image sensor under low light. In this paper, the physical and statistical model of the random telegraph signal noise in the pixel source follower based on the binomial distribution is set up. The number of electrons captured or released by the oxide traps in the unit time is described as the random variables which obey the binomial distribution. As a result,the output states and the corresponding probabilities of the first and the second samples of the correlated double sampling circuit are acquired. The standard deviation of the output states after the correlated double sampling circuit can be obtained accordingly. In the simulation section, one hundred thousand samples of the source follower MOSFET have been simulated,and the simulation results show that the proposed model has the similar statistical characteristics with the existing models under the effect of the channel length and the density of the oxide trap. Moreover, the noise histogram of the proposed model has been evaluated at different environmental temperatures.

Precise measurement of geometric and physical quantities in cutting tools inspection and condition monitoring: A review

As one of the most important terminals in machining, cutting tools have been widely used for components manufacturing in aerospace and other industries. The quality of these components and processing efficiency are closely linked to the performance of cutting tools. Therefore, it is essential and critical to inspect the cutting tools and monitor the condition during the stage of manufacturing and machining. This review aims to discuss and summarize the key problems, methods,and techniques from the perspective of the tool geometric and the physical quantities measurement,including machine vision, physical sensors and data processing. It is worth mentioning that we focus on the topic of precision measurement methods and discuss universal solutions by identifying the common characteristics of the measured quantities. Eventually, the challenges and future trends for the development of in-depth research and practical applications are concluded. The research and application of precise measurement techniques for geometric and physical quantities will better promote the development of intelligent manufacturing.

Micro/Nanofiber Optical Sensors

As a low-dimensional optical fiber with diameter close to or below the wavelength of light,optical micro/nanofiber(MNF)offers a number of favorable properties for optical sensing,which have been exploited in a variety of sensing applications,including physical,chemical,and biological sensors.In this paper we review the principles and applications of silica,glass,and polymer optical micro/nanofibers for physical and chemical sensing.