Capacitive touch sensor

2018 ◽  
Vol 35 (3) ◽  
pp. 153-157 ◽  
Author(s):  
Samuel Zuk ◽  
Alena Pietrikova ◽  
Igor Vehec

Purpose The purpose of this paper is to analyse the possibilities of mechanical switch replacement by capacitive film touch sensor in applications requiring high reliability and short response time. Advantage of replacing mechanical switch by capacitive touch sensor is no mechanical wear and possible implementation of sensor in application where the switch could not be used or where the flexibility of the sensor substrate is required. The aim of this work is to develop a capacitive touch sensor with the advantage of maximum mechanical resistance, short response time and high sensitivity. Design/methodology/approach Based on various possible sensors layouts, the authors realized 18 different (14 self-capacitance and four mutual capacitance) topologies of capacitive sensor for touch applications. Three different technologies – PCB, LTCC and polymer technology – were used to characterize sensor’s behaviour. For precise characterization of different layouts realized on various substrates, the authors used integrated circuit FDC2214 capacitance-to-digital converter. Findings Sensing range of the capacitive touch (proximity) sensor is affected by the per cent of area covered by the sensor, and it does not depend on topology of sensor. The highest sensing range offers PCB technology. Flexible substrates can be used as proper substituent to rigid PCB. Originality/value The novelty of this work lies in finding the touch capacitive sensors that allow shorter switching times compared to standard mechanical switches.

RSC Advances ◽  
2016 ◽  
Vol 6 (43) ◽  
pp. 37085-37092 ◽  
Author(s):  
Ying Yang ◽  
Li Sun ◽  
Xiangting Dong ◽  
Hui Yu ◽  
Tingting Wang ◽  
...  

Fe3O4nanoparticles-decorated reduced graphene oxide nanocomposites have been successfully synthesized using solvothermal-pyrolytic method. They have superior gas sensing performance with low detection limit, high sensitivity and short response time.


2021 ◽  
Vol 17 (7) ◽  
pp. 1249-1272
Author(s):  
Xiao-Lin Wang ◽  
Xiao Han ◽  
Xiao-Ying Tang ◽  
Xiao-Jun Chen ◽  
Han-Jun Li

With the development of nanomaterials, fluorescent nanoprobes have attracted enormous attention in the fields of chemical sensing, optical materials, and biological detection. In this paper, the advantages of “off–on” fluorescent nanoprobes in disease detection, such as high sensitivity and short response time, are attentively highlighted. The characteristics, sensing mechanisms, and classifications of disease-related target substances, along with applications of these nanoprobes in cancer diagnosis and therapy are summarized systematically. In addition, the prospects of “off–on” fluorescent nanoprobe in disease detection are predicted. In this review, we presented information from all the papers published in the last 5 years discussing “off–on” fluorescent nanoprobes. This review was written in the hopes of being useful to researchers who are interested in further developing fluorescent nanoprobes. The characteristics of these nanoprobes are explained systematically, and data references and supports for biological analysis, clinical drug improvement, and disease detection have been provided appropriately.


RSC Advances ◽  
2019 ◽  
Vol 9 (22) ◽  
pp. 12585-12589 ◽  
Author(s):  
Fa-Heng Zhang ◽  
Rui-Xue Jiang ◽  
Wei Cao ◽  
Bin Du ◽  
Ding-Yuan Cao ◽  
...  

Anisotropic fluorescent nanofibers constructed from the self-assembled perylene bisimide derivative and poly(vinylidene fluoride) show high sensitivity and short response time to aniline vapor.


2018 ◽  
Vol 7 (1) ◽  
pp. 219-226 ◽  
Author(s):  
Jan Erfkamp ◽  
Margarita Guenther ◽  
Gerald Gerlach

Abstract. This article describes a low-cost sensor for the detection of ethanol in alcoholic beverages, which combines alcohol-sensitive hydrogels based on acrylamide and bisacrylamide and piezoresistive sensors. For reproducible measurements, the reversible swelling and deswelling of the hydrogel were shown via microscopy. The response time of the sensor depends on the swelling kinetics of the hydrogel. The selectivity of the hydrogel was tested in different alcohols. In order to understand the influence of monomer and crosslinker content on the swelling degree and on the sensitivity of the hydrogels, gels with variable concentrations of acrylamide and bisacrylamide were synthesized and characterized in different aqueous solutions with alcohol contents. The first measurements of such hydrogel-based piezoresistive ethanol sensors demonstrated a high sensitivity and a short response time over several measuring cycles.


2015 ◽  
Vol 3 (5) ◽  
pp. 919-925 ◽  
Author(s):  
Shi-Li Shen ◽  
Xin-Peng Chen ◽  
Xiao-Fan Zhang ◽  
Jun-Ying Miao ◽  
Bao-Xiang Zhao

A novel rhodamine B-based lysosomal pH probe RML was developed. RML responded to acidic pH with short response time, high selectivity and high sensitivity and could detect lysosomal pH change in living cells.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1915
Author(s):  
Shenawar Ali Khan ◽  
Muhammad Saqib ◽  
Muhammad Muqeet Rehman ◽  
Hafiz Mohammad Mutee Ur Rehman ◽  
Sheik Abdur Rahman ◽  
...  

A novel composite based on a polymer (P(VDF-TrFE)) and a two-dimensional material (graphene flower) was proposed as the active layer of an interdigitated electrode (IDEs) based humidity sensor. Silver (Ag) IDEs were screen printed on a flexible polyethylene terephthalate (PET) substrate followed by spin coating the active layer of P(VDF-TrFE)/graphene flower on its surface. It was observed that this sensor responds to a wide relative humidity range (RH%) of 8–98% with a fast response and recovery time of 0.8 s and 2.5 s for the capacitance, respectively. The fabricated sensor displayed an inversely proportional response between capacitance and RH%, while a directly proportional relationship was observed between its impedance and RH%. P(VDF-TrFE)/graphene flower-based flexible humidity sensor exhibited high sensitivity with an average change of capacitance as 0.0558 pF/RH%. Stability of obtained results was monitored for two weeks without any considerable change in the original values, signifying its high reliability. Various chemical, morphological, and electrical characterizations were performed to comprehensively study the humidity-sensing behavior of this advanced composite. The fabricated sensor was successfully used for the applications of health monitoring and measuring the water content in the environment.


2021 ◽  
pp. 1-1
Author(s):  
Valliammai Palaniappan ◽  
Masoud Panahi ◽  
Dinesh Maddipatla ◽  
Xingzhe Zhang ◽  
Simin Masihi ◽  
...  

2016 ◽  
Vol 4 (15) ◽  
pp. 3113-3118 ◽  
Author(s):  
Yue Teng ◽  
Le Xin Song ◽  
Wei Liu ◽  
Zhe Yuan Xu ◽  
Qing Shan Wang ◽  
...  

We successfully synthesized ZnGa2O4 microflowers self-assembled by hexagonal single-crystalline nanopetals. The ZnGa2O4 crystal exhibits improved solar-blind detection performance such as short response time, large light to dark current ratio and high photocurrent stability under zero bias voltage.


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