Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applications
Autor(a) principal: | |
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Data de Publicação: | 2021 |
Outros Autores: | , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/1822/74651 |
Resumo: | This work describes the development of a capacitive-type sensor created from nanoporous anodic aluminium oxide (NP-AAO) prepared by the one-step anodization method conducted in potentiostatic mode and performed in a low-cost homemade system. A series of samples were prepared via an anodization campaign carried out on different acid electrolytes, in which the anodization parameters were adjusted to investigate the effect of pore size and porosity on the capacitive sensing performance. Two sensor test cases are investigated. The first case explores the use of highly uniform NP-AAO structures for humidity sensing applications while the second analyses the use of NP-AAO as a capacitive touch sensor for biological applications, namely, to detect the presence of small objects such as bacterial colonies of Escherichia Coli. A mathematical model based on equivalent electrical circuits was developed to evaluate the effect of humidity condensation (inside the pores) on the sensor capacitance and also to estimate the capacitance change of the sensor due to pore blocking by the presence of a certain number of bacterial microorganisms. Regarding the humidity sensing test cases, it was found that the sensitivity of the sensor fabricated in a phosphoric acid solution reaches up to 39 (pF/RH%), which is almost three times higher than the sensor fabricated in oxalic acid and about eight times higher than the sensor fabricated in sulfuric acid. Its improved sensitivity is explained in terms of the pore size effect on the mean free path and the loss of Brownian energy of the water vapour molecules. Concerning the touch sensing test case, it is demonstrated that the NP-AAO structures can be used as capacitive touch sensors because the magnitude of the capacitance change directly depends on the number of bacteria that cover the nanopores; the fraction of the electrode area activated by bacterial pore blocking is about 4.4% and 30.2% for B1 (E. Coli OD600nm=0.1) and B2 (E. Coli OD600nm=1) sensors, respectively. |
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Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applicationsCapacitive-type sensorSensitivityAnodizationNanoporous anodic aluminaScience & TechnologyThis work describes the development of a capacitive-type sensor created from nanoporous anodic aluminium oxide (NP-AAO) prepared by the one-step anodization method conducted in potentiostatic mode and performed in a low-cost homemade system. A series of samples were prepared via an anodization campaign carried out on different acid electrolytes, in which the anodization parameters were adjusted to investigate the effect of pore size and porosity on the capacitive sensing performance. Two sensor test cases are investigated. The first case explores the use of highly uniform NP-AAO structures for humidity sensing applications while the second analyses the use of NP-AAO as a capacitive touch sensor for biological applications, namely, to detect the presence of small objects such as bacterial colonies of Escherichia Coli. A mathematical model based on equivalent electrical circuits was developed to evaluate the effect of humidity condensation (inside the pores) on the sensor capacitance and also to estimate the capacitance change of the sensor due to pore blocking by the presence of a certain number of bacterial microorganisms. Regarding the humidity sensing test cases, it was found that the sensitivity of the sensor fabricated in a phosphoric acid solution reaches up to 39 (pF/RH%), which is almost three times higher than the sensor fabricated in oxalic acid and about eight times higher than the sensor fabricated in sulfuric acid. Its improved sensitivity is explained in terms of the pore size effect on the mean free path and the loss of Brownian energy of the water vapour molecules. Concerning the touch sensing test case, it is demonstrated that the NP-AAO structures can be used as capacitive touch sensors because the magnitude of the capacitance change directly depends on the number of bacteria that cover the nanopores; the fraction of the electrode area activated by bacterial pore blocking is about 4.4% and 30.2% for B1 (E. Coli OD600nm=0.1) and B2 (E. Coli OD600nm=1) sensors, respectively.This research was funded by: the Portuguese Foundation for Science and Technology (FCT) under the strategic funding grants UIDB/04029/2020, UIDB/04650/2020 and UIDB/04469/20 units; and, the European Regional Development Fund under the scope of Norte2020 program grant NORTE-01-0145-FEDER-000004, BioTecNorte.info:eu-repo/semantics/publishedVersionMultidisciplinary Digital Publishing Institute (MDPI)Universidade do MinhoCarneiro, Joaquim A. O.Ribeiro, ArturMiranda, FilipeSegundo, Iran RochaLandi Júnior, SalmonTeixeira, Vasco M. P.Costa, Manuel F. M.2021-11-032021-11-03T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/1822/74651engCarneiro, Joaquim O.; Ribeiro, Artur; Miranda, Filipe; Segundo, Iran Rocha; Salmon Landi, Jr.; Teixeira, Vasco; Costa, Manuel F. M., Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applications. Sensors, 21(21), 7317, 20211424-82201424-822010.3390/s2121731734770624http://www.mdpi.com/journal/sensorsinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-21T12:15:31Zoai:repositorium.sdum.uminho.pt:1822/74651Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T19:07:58.237215Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applications |
title |
Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applications |
spellingShingle |
Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applications Carneiro, Joaquim A. O. Capacitive-type sensor Sensitivity Anodization Nanoporous anodic alumina Science & Technology |
title_short |
Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applications |
title_full |
Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applications |
title_fullStr |
Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applications |
title_full_unstemmed |
Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applications |
title_sort |
Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applications |
author |
Carneiro, Joaquim A. O. |
author_facet |
Carneiro, Joaquim A. O. Ribeiro, Artur Miranda, Filipe Segundo, Iran Rocha Landi Júnior, Salmon Teixeira, Vasco M. P. Costa, Manuel F. M. |
author_role |
author |
author2 |
Ribeiro, Artur Miranda, Filipe Segundo, Iran Rocha Landi Júnior, Salmon Teixeira, Vasco M. P. Costa, Manuel F. M. |
author2_role |
author author author author author author |
dc.contributor.none.fl_str_mv |
Universidade do Minho |
dc.contributor.author.fl_str_mv |
Carneiro, Joaquim A. O. Ribeiro, Artur Miranda, Filipe Segundo, Iran Rocha Landi Júnior, Salmon Teixeira, Vasco M. P. Costa, Manuel F. M. |
dc.subject.por.fl_str_mv |
Capacitive-type sensor Sensitivity Anodization Nanoporous anodic alumina Science & Technology |
topic |
Capacitive-type sensor Sensitivity Anodization Nanoporous anodic alumina Science & Technology |
description |
This work describes the development of a capacitive-type sensor created from nanoporous anodic aluminium oxide (NP-AAO) prepared by the one-step anodization method conducted in potentiostatic mode and performed in a low-cost homemade system. A series of samples were prepared via an anodization campaign carried out on different acid electrolytes, in which the anodization parameters were adjusted to investigate the effect of pore size and porosity on the capacitive sensing performance. Two sensor test cases are investigated. The first case explores the use of highly uniform NP-AAO structures for humidity sensing applications while the second analyses the use of NP-AAO as a capacitive touch sensor for biological applications, namely, to detect the presence of small objects such as bacterial colonies of Escherichia Coli. A mathematical model based on equivalent electrical circuits was developed to evaluate the effect of humidity condensation (inside the pores) on the sensor capacitance and also to estimate the capacitance change of the sensor due to pore blocking by the presence of a certain number of bacterial microorganisms. Regarding the humidity sensing test cases, it was found that the sensitivity of the sensor fabricated in a phosphoric acid solution reaches up to 39 (pF/RH%), which is almost three times higher than the sensor fabricated in oxalic acid and about eight times higher than the sensor fabricated in sulfuric acid. Its improved sensitivity is explained in terms of the pore size effect on the mean free path and the loss of Brownian energy of the water vapour molecules. Concerning the touch sensing test case, it is demonstrated that the NP-AAO structures can be used as capacitive touch sensors because the magnitude of the capacitance change directly depends on the number of bacteria that cover the nanopores; the fraction of the electrode area activated by bacterial pore blocking is about 4.4% and 30.2% for B1 (E. Coli OD600nm=0.1) and B2 (E. Coli OD600nm=1) sensors, respectively. |
publishDate |
2021 |
dc.date.none.fl_str_mv |
2021-11-03 2021-11-03T00:00:00Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/1822/74651 |
url |
http://hdl.handle.net/1822/74651 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Carneiro, Joaquim O.; Ribeiro, Artur; Miranda, Filipe; Segundo, Iran Rocha; Salmon Landi, Jr.; Teixeira, Vasco; Costa, Manuel F. M., Development of capacitive-type sensors by electrochemical anodization: humidity and touch sensing applications. Sensors, 21(21), 7317, 2021 1424-8220 1424-8220 10.3390/s21217317 34770624 http://www.mdpi.com/journal/sensors |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Multidisciplinary Digital Publishing Institute (MDPI) |
publisher.none.fl_str_mv |
Multidisciplinary Digital Publishing Institute (MDPI) |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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