Fabrication of Skin-Like Sensors in Thin Polymeric Membranes
Autor(a) principal: | |
---|---|
Data de Publicação: | 2019 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10362/92225 |
Resumo: | Recently, research in health care improved the creation of devices that accurately monitor various physiological stimuli (wearable devices) which provide better health care and help to predict possible diseases through continuous data collection. However, wearable devices are at an early stage of development and several improvements must be made, both at structural and materials level. Some examples of devices on the market such as smartwatches or fitness bands are still very bulky and the goal is to make them as small and functional as possible. This work focuses on the improvement of fabrication process steps of pressure sensors, based on micro-structured thin polymeric films of Polydimethylsiloxane (PDMS) or Parylene C, namely micro-structuration techniques and electrode deposition. To create domeshaped structures, Polystyrene (PS) microspheres were deposited by Langmuir-Blodgett (LB) process over Parylene C and then subjected to a Reactive Ion Etching (RIE) process to create the mold. Pyramidal structures were made by anisotropic etching of silicon with potassium hydroxide (KOH) to make molds. Both molds were further used to produce micro-structured PDMS films by soft lithography. Through these techniques, PDMS domes with diameters between 2.3 m and 3.0 m and heights between 1.6 m and 1.7 m, and PDMS pyramids with a size of 50 m to 100 m and a height of 34.3 m to 66.4 m were achieved. To work as a piezoresistive pressure sensor, the micro-structures must be covered with a conductive layer that will play the role of electrode. To overcome adhesion issues between PDMS and some metals, the possibility of using a thin film of Parylene C on top of PDMS was studied. The metals explored were aluminium, copper, and titanium with gold, where the latter presented better adhesion and electrical properties. The developed micro-structured films were assembled and tested as piezoresistive or capacitive pressure sensors achieving sensitivities up to -1.1 102 kPa1 and 3.1 102 kPa1 respectively. |
id |
RCAP_bdf2d5423b50bb4e891f13fdf61bb4b3 |
---|---|
oai_identifier_str |
oai:run.unl.pt:10362/92225 |
network_acronym_str |
RCAP |
network_name_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository_id_str |
7160 |
spelling |
Fabrication of Skin-Like Sensors in Thin Polymeric MembranesWearable devicesPDMSParylene CPressure sensorsMetals adhesionDomínio/Área Científica::Engenharia e Tecnologia::NanotecnologiaRecently, research in health care improved the creation of devices that accurately monitor various physiological stimuli (wearable devices) which provide better health care and help to predict possible diseases through continuous data collection. However, wearable devices are at an early stage of development and several improvements must be made, both at structural and materials level. Some examples of devices on the market such as smartwatches or fitness bands are still very bulky and the goal is to make them as small and functional as possible. This work focuses on the improvement of fabrication process steps of pressure sensors, based on micro-structured thin polymeric films of Polydimethylsiloxane (PDMS) or Parylene C, namely micro-structuration techniques and electrode deposition. To create domeshaped structures, Polystyrene (PS) microspheres were deposited by Langmuir-Blodgett (LB) process over Parylene C and then subjected to a Reactive Ion Etching (RIE) process to create the mold. Pyramidal structures were made by anisotropic etching of silicon with potassium hydroxide (KOH) to make molds. Both molds were further used to produce micro-structured PDMS films by soft lithography. Through these techniques, PDMS domes with diameters between 2.3 m and 3.0 m and heights between 1.6 m and 1.7 m, and PDMS pyramids with a size of 50 m to 100 m and a height of 34.3 m to 66.4 m were achieved. To work as a piezoresistive pressure sensor, the micro-structures must be covered with a conductive layer that will play the role of electrode. To overcome adhesion issues between PDMS and some metals, the possibility of using a thin film of Parylene C on top of PDMS was studied. The metals explored were aluminium, copper, and titanium with gold, where the latter presented better adhesion and electrical properties. The developed micro-structured films were assembled and tested as piezoresistive or capacitive pressure sensors achieving sensitivities up to -1.1 102 kPa1 and 3.1 102 kPa1 respectively.Igreja, RuiPinto, JoanaRUNFernandes, Paulo Edgar Geraldes2020-02-05T16:35:23Z2019-1220192019-12-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10362/92225enginfo: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:RCAAP2024-03-11T04:40:59Zoai:run.unl.pt:10362/92225Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:37:27.215950Repositório 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 |
Fabrication of Skin-Like Sensors in Thin Polymeric Membranes |
title |
Fabrication of Skin-Like Sensors in Thin Polymeric Membranes |
spellingShingle |
Fabrication of Skin-Like Sensors in Thin Polymeric Membranes Fernandes, Paulo Edgar Geraldes Wearable devices PDMS Parylene C Pressure sensors Metals adhesion Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia |
title_short |
Fabrication of Skin-Like Sensors in Thin Polymeric Membranes |
title_full |
Fabrication of Skin-Like Sensors in Thin Polymeric Membranes |
title_fullStr |
Fabrication of Skin-Like Sensors in Thin Polymeric Membranes |
title_full_unstemmed |
Fabrication of Skin-Like Sensors in Thin Polymeric Membranes |
title_sort |
Fabrication of Skin-Like Sensors in Thin Polymeric Membranes |
author |
Fernandes, Paulo Edgar Geraldes |
author_facet |
Fernandes, Paulo Edgar Geraldes |
author_role |
author |
dc.contributor.none.fl_str_mv |
Igreja, Rui Pinto, Joana RUN |
dc.contributor.author.fl_str_mv |
Fernandes, Paulo Edgar Geraldes |
dc.subject.por.fl_str_mv |
Wearable devices PDMS Parylene C Pressure sensors Metals adhesion Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia |
topic |
Wearable devices PDMS Parylene C Pressure sensors Metals adhesion Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia |
description |
Recently, research in health care improved the creation of devices that accurately monitor various physiological stimuli (wearable devices) which provide better health care and help to predict possible diseases through continuous data collection. However, wearable devices are at an early stage of development and several improvements must be made, both at structural and materials level. Some examples of devices on the market such as smartwatches or fitness bands are still very bulky and the goal is to make them as small and functional as possible. This work focuses on the improvement of fabrication process steps of pressure sensors, based on micro-structured thin polymeric films of Polydimethylsiloxane (PDMS) or Parylene C, namely micro-structuration techniques and electrode deposition. To create domeshaped structures, Polystyrene (PS) microspheres were deposited by Langmuir-Blodgett (LB) process over Parylene C and then subjected to a Reactive Ion Etching (RIE) process to create the mold. Pyramidal structures were made by anisotropic etching of silicon with potassium hydroxide (KOH) to make molds. Both molds were further used to produce micro-structured PDMS films by soft lithography. Through these techniques, PDMS domes with diameters between 2.3 m and 3.0 m and heights between 1.6 m and 1.7 m, and PDMS pyramids with a size of 50 m to 100 m and a height of 34.3 m to 66.4 m were achieved. To work as a piezoresistive pressure sensor, the micro-structures must be covered with a conductive layer that will play the role of electrode. To overcome adhesion issues between PDMS and some metals, the possibility of using a thin film of Parylene C on top of PDMS was studied. The metals explored were aluminium, copper, and titanium with gold, where the latter presented better adhesion and electrical properties. The developed micro-structured films were assembled and tested as piezoresistive or capacitive pressure sensors achieving sensitivities up to -1.1 102 kPa1 and 3.1 102 kPa1 respectively. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-12 2019 2019-12-01T00:00:00Z 2020-02-05T16:35:23Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10362/92225 |
url |
http://hdl.handle.net/10362/92225 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
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.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 |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
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 |
repository.mail.fl_str_mv |
|
_version_ |
1799137991189331968 |