Modification of silicon oxide substrates with functional ultrathin organic films
Lead Research Organisation:
University of St Andrews
Department Name: Chemistry
Abstract
The field of micro-electromechanical systems (MEMS) made of silicon has rapidly expanded over the last few years. These miniature mechanical transducers are used in many different areas. Micromachined mechanical sensors include for example pressure, force, acceleration, torque, inertial, and flow sensors. The market for such micromachined mechanical transducers is huge, accounting for the largest part of the overall MEMS market in the recent past. This is likely to continue in the near future. One reason for this interest is reflected in the many areas where MEMS have the potential to bring significant breakthroughs. They will, for example, play an increasingly important role in the areas of health care, e.g as patient monitoring systems, both portable and in hospitals (bio MEMS), and energy (e.g. in the form of micro fuel cell systems based on MEMS technology), areas which are both on the list of the current grand challenges in science.
However, to date MEMS are currently used in low- or medium-volume applications. One of the main obstacles preventing their wider adoption is the need to protect the surfaces of these entities from detrimental environmental influences, such as humidity, to ensure their reliable, long-term performance. There is also a desire to be able to functionalise the surfaces of these entities in an application-specific manner, such as being able to provide a surface which is sensitive to protein adsorption. Despite the many advances that have been made in the field of fabrication of MEMS, there remains a need to improve the ability to reliably chemically coat or selectively functionalise these surfaces as this often affects the reliability and performance of MEMS.
The project will contribute to the basic knowledge of surface chemistry in general, with novel reactions performed at silicon oxide surfaces in solution and in the gas phase. These deposition processes should open entirely new avenues for the coating and functionalisation of silicon oxide surfaces. A versatile and flexible coating procedure in connection with microstructures and MEMS is currently not available, and we will harness the potential of this procedure to allow flexible surface modification. The generation of a successful vapour phase modification methodology is pivotal for the application in connection with MEMS and will lead to their faster and wider adoption, which may have significant potential impact on fields such as healthcare and energy. The project therefore also contributes to ensuring that the UK will play a significant role in the MEMS market on a long term scale.
However, to date MEMS are currently used in low- or medium-volume applications. One of the main obstacles preventing their wider adoption is the need to protect the surfaces of these entities from detrimental environmental influences, such as humidity, to ensure their reliable, long-term performance. There is also a desire to be able to functionalise the surfaces of these entities in an application-specific manner, such as being able to provide a surface which is sensitive to protein adsorption. Despite the many advances that have been made in the field of fabrication of MEMS, there remains a need to improve the ability to reliably chemically coat or selectively functionalise these surfaces as this often affects the reliability and performance of MEMS.
The project will contribute to the basic knowledge of surface chemistry in general, with novel reactions performed at silicon oxide surfaces in solution and in the gas phase. These deposition processes should open entirely new avenues for the coating and functionalisation of silicon oxide surfaces. A versatile and flexible coating procedure in connection with microstructures and MEMS is currently not available, and we will harness the potential of this procedure to allow flexible surface modification. The generation of a successful vapour phase modification methodology is pivotal for the application in connection with MEMS and will lead to their faster and wider adoption, which may have significant potential impact on fields such as healthcare and energy. The project therefore also contributes to ensuring that the UK will play a significant role in the MEMS market on a long term scale.
Planned Impact
The planned methodologies are relevant to many technological processes and may be directly exploited for applications where a tailored interaction between siliocn oxide surfaces and their environment is required. It is hoped that successful experiments will initiate the adaptation of similar systems by other researchers to explore further the potential of this approach.
In addition to the preparation of ultrathin organic films from solution, we also plan to apply films from the gas phase; this process will be applicable to a high number of substrates simultaneously and will be suitable to coat small structures such as MEMS. This is of high relevance for industrial applications since wet chemistry is often not desirable on such scales for technical, economic, and ecological reasons.
It is therefore hoped that the results will initiate the adaptation of similar procedures by industry. The project sits squarely on the interface between materials and surface chemistry and the insights, scientific results and training that derive from the programme will contribute significantly to the current development of MEMS devices.
Potential beneficiaries are therefore the academic community as well as the industrial sector of MEMS. As a consequence this methodology will be beneficial for society in general if the methods developed will be used in connection with MEMS for example in areas such as health care and energy in the future.
In addition to the preparation of ultrathin organic films from solution, we also plan to apply films from the gas phase; this process will be applicable to a high number of substrates simultaneously and will be suitable to coat small structures such as MEMS. This is of high relevance for industrial applications since wet chemistry is often not desirable on such scales for technical, economic, and ecological reasons.
It is therefore hoped that the results will initiate the adaptation of similar procedures by industry. The project sits squarely on the interface between materials and surface chemistry and the insights, scientific results and training that derive from the programme will contribute significantly to the current development of MEMS devices.
Potential beneficiaries are therefore the academic community as well as the industrial sector of MEMS. As a consequence this methodology will be beneficial for society in general if the methods developed will be used in connection with MEMS for example in areas such as health care and energy in the future.
Publications
Parkin JD
(2018)
Direct Organocatalytic Enantioselective Functionalization of SiOx Surfaces.
in Angewandte Chemie (International ed. in English)
Neyyappadath R
(2018)
Acylative Kinetic Resolution of Alcohols Using a Recyclable Polymer-Supported Isothiourea Catalyst in Batch and Flow
in ACS Catalysis
Parkin J
(2018)
Direct Organocatalytic Enantioselective Functionalization of SiO x Surfaces
in Angewandte Chemie
Chisholm R
(2016)
Isothiourea-Mediated Organocatalytic Michael Addition-Lactonization on a Surface: Modification of SAMs on Silicon Oxide Substrates.
in Langmuir : the ACS journal of surfaces and colloids
Parkin JD
(2016)
Contact-free experimental determination of the static flexural spring constant of cantilever sensors using a microfluidic force tool.
in Beilstein journal of nanotechnology
Parkin JD
(2014)
Calibration of the torsional and lateral spring constants of cantilever sensors.
in Nanotechnology
Adamkiewicz M
(2014)
Bis(trifluoromethyl)methylene addition to vinyl-terminated SAMs: a gas-phase C-C bond-forming reaction on a surface.
in Langmuir : the ACS journal of surfaces and colloids
Description | Silicon oxide substrates pre-covered with a vinyl-terminated monomolecular film were chemically modified by the addition of a bis(tri-fluoromethyl)methylene group in a rare gas-phase C-C bond-forming reaction to directly generate films carrying terminal CF3 groups without the addition of a catalyst. In addition we demonstrated that ultrathin organic films on silicon oxide substrates can be modified organocatalytically in situ. Traditional methods to prepare chiral surfaces involve either the adsorption of a chiral molecule onto an achiral surface, or adsorption of a species that forms a chiral template creating lattices with long range order. To date only limited alternative strategies to prepare chiral surfaces have been reported. We developed a "bottom-up" approach that allows the preparation of chiral surfaces by direct enantioselective organocatalytic reactions on a functionalized silicon oxide supported self-assembled monolayer (SAM). The enantioselective modification of ultrathin organic films in situ is of potential interest in the life sciences where a separation of enantiomers is often crucial. |
Exploitation Route | Coating substrates with functional ultrathin organic films is highly relevant in the life sciences and in biotechnology. The methods we developed could for example be employed in connection with MEMS and NEMS, which are made of silicon and are playing an increasingly important role in our daily life. A versatile and flexible coating procedure in connection with microstructures and MEMS is currently not available. The procedures we developed have the potential to enable a flexible organic surface modification. |
Sectors | Chemicals,Education,Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology |
Description | There are many areas where interface technology plays an important role and the reliable control of a functional surface has exciting implications to many of them. The technology we developed may be particularly relevant within the life sciences, microfluidics and sensing applications, all of which would clearly benefit from procedures that facilitate controlled interactions on a surface, such as biomolecule interactions with proteins. Such functional surfaces will play an important role in the future design of advanced materials. During this project a PhD student and a PDRA received thorough and excellent training in areas that are highly relevant in modern technology and science. They acquired skills in organic synthesis, surface analytical techniques and methods, coating procedures, and ultrathin organic films. The project therefore directly contributed to the knowledge and skills of highly trained people in the UK. |
Sector | Chemicals,Other |
Impact Types | Societal,Economic |
Description | EPSRC Centre for Doctoral Training in Critical Resource Catalysis - CRITICAT |
Amount | £60,000 (GBP) |
Funding ID | EP/L016419/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 09/2017 |
End | 03/2021 |
Description | Impact Acceleration Account |
Amount | £18,291 (GBP) |
Funding ID | EP/K503940/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 07/2014 |
End | 07/2015 |
Title | Data underpinning - Isothiourea mediated organocatalytic Michael addition-lactonization on a surface: modification of SAMs on silicon oxide substrates |
Description | Data underpinning 'Isothiourea mediated organocatalytic Michael addition-lactonization on a surface: modification of SAMs on silicon oxide substrates' |
Type Of Material | Database/Collection of data |
Year Produced | 2016 |
Provided To Others? | Yes |
Title | Data underpinning Samuel Smith's thesis |
Description | The data files are embargoed until 06/11/2020. |
Type Of Material | Database/Collection of data |
Year Produced | 2020 |
Provided To Others? | Yes |
Title | Direct organocatalytic enantioselective functionalization of SiOx surfaces (dataset) |
Description | |
Type Of Material | Database/Collection of data |
Year Produced | 2018 |
Provided To Others? | Yes |
Title | data underpinning "Evaluating polymer-supported isothiourea catalysis in industrially-preferable solvents for the acylative kinetic resolution of secondary and tertiary heterocyclic alcohols in batch and flow" |
Description | data for publication |
Type Of Material | Database/Collection of data |
Year Produced | 2018 |
Provided To Others? | Yes |
Title | data underpinning -Acylative Kinetic Resolution of Alcohols Using a Recyclable Polymer-Supported Isothiourea Catalyst in Batch and Flow |
Description | dataset acquired in relation to "Acylative Kinetic Resolution of Alcohols Using a Recyclable Polymer-Supported Isothiourea Catalyst in Batch and Flow" |
Type Of Material | Database/Collection of data |
Year Produced | 2018 |
Provided To Others? | Yes |
Impact | too early to say |
Description | 250th American Chemical Society Meeting and Exposition, Boston, USA |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Industry/Business |
Results and Impact | Talk title: Organocatalytic functionalization of self-assembled monolayers on SiO2 Poster title: Isothiourea mediated surface modification of self-assembled monolayers on SiO2 |
Year(s) Of Engagement Activity | 2015 |
Description | 44th Scottish Regional Organic Division RSC Meeting, University of Aberdeen |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Postgraduate students |
Results and Impact | Poster presentation: Organocatalytic surface modification: Synthesis, characterisation and chemical force discrimination of self-assembled monolayers on SiO2 |
Year(s) Of Engagement Activity | 2013,2016 |
Description | 5th UK-Japanese Symposium on Asymmetric Catalysis, University of Manchester |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Postgraduate students |
Results and Impact | Poster presentation: Organocatalytic surface modification: Synthesis, characterisation and chemical force discrimination of self-assembled monolayers on SiO2 |
Year(s) Of Engagement Activity | 2016 |
Description | Final Year Postgraduate Symposium, University of St Andrews, |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Postgraduate students |
Results and Impact | Oral presentation: Organocatalytic surface modification: Synthesis, characterisation and chemical force discrimination of self-assembled monolayers on SiO2 |
Year(s) Of Engagement Activity | 2015 |
Description | Organic Research Seminar, University of St Andrews |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Postgraduate students |
Results and Impact | Organocatalytic surface modification of vinyl terminated SAMs |
Year(s) Of Engagement Activity | 2015 |
Description | University of St Andrews Industry Chemistry Forum |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Undergraduate students |
Results and Impact | Poster title: Isothiourea mediated surface modification of self-assembled monolayers on SiO2 |
Year(s) Of Engagement Activity | 2015 |