- Theme:
- Nanoelectronics
Laboratory tests are a vital part of the accurate diagnosis of a patientââ¬â¢s condition, with around 1 billion tests performed in the UK each year. To enable the routine application of predictive, preventive and personalized healthcare, these biochemical tests will have to be performed at a much larger scale, at much lower cost, and preferably at point-of-care locations rather than at clinical laboratories. The realization of this highly desirable situation necessitates the development of new, more cost-effective, technologies for biosensor fabrication. Recently, silicon nanowire biosensors have been reported suitable for real-time, high sensitivity, high selectivity and label-free biosensing. The high sensitivity is due to the nanoscale diameter of nanowires, which is comparable to that of biomolecules. However, while the feasibility of nanowire biosensors has been demonstrated, current fabrication approaches are expensive due to the use of silicon-on-insulator wafers and e-beam lithography.
This project aims to develop a low-cost fabrication process for silicon nanowire biosensors using thin film transistor technology. The use of low cost glass or plastic substrates requires a low thermal budget process for the nanowire biosensor fabrication. Amorphous silicon could be used to fabricate the silicon nanowires, but the mobility is very low. In this project, nickel-induced lateral crystallization is being researched to convert amorphous silicon into polycrystalline silicon using a low temperature anneal. Polycrystalline silicon has a dramatically higher value of mobility than amorphous silicon and hence should give better sensor performance. Two nanowire configurations are being investigated, namely Si-on-Oxide and Si-on-Air. The Si-on-Oxide structure has the advantage of a simple fabrication process, whereas the Si-on-Air structure has the advantage of allowing biomolecule attachment all around the nanowire and hence should have higher sensitivity. Fig.1(a) shows that crystallization proceeds more rapidly in the Si-on-Air structure, which should allow crystallization to be achieved at a lower temperature. We are also investigating the use of fluorine implantation to enhance the crystallization. Fig.1 (b) shows that fluorine aids crystallization at or below a critical dose of 1E15 cm-2.
Primary investigator
- Professor Peter Ashburn
Secondary investigator
- Sun, Kai
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
semiconductor nanowires offer numerous opportunities for next generation subwavelength optical information processors. As the one dimensional building block element a collection of them can assume different functions in three units of nanoscale photonic circuitry;(i) light generation (active part), (ii) interconnects (passive) and (iii) light detection module. All of these three parts operate on the basis of waveguide principles, although several other issues can affect on the functionality of each individual core. These include coupling, confinement, loss, thermoptics and electrooptics effects, and a number of other material or geometrical concerns. Therefore, this project aims to rigorously investigate and model arbitrary geometric semiconductor nanowire structures fabricated by top-down and bottom-up method, light generation mechanism and perform optical characterization of the nanowires using an integrated near field scanning optical microscope with Raman spectrometer and Laser spectroscopy. All modelling processes are based on commercial software and finite difference time domain algorithm (FDTD) to solve Maxwellââ¬â¢s equations for the desired spatial structure. The semiconductor nanowires of interest are silicon, Silica, zinc oxide, and tantalum pentoxide and heterostructure silicon-germanium. The work is then expanded to more complicated cross sections and functional geometries for various material indices. The results can be then employed as the platform to
- explore the possibility of integrating passive nanowire waveguides with other active photonic and electronic devices in nanoscale for more practical architectures. - invistigate the the applicability of Light modulation techniques in nanowire for computing and communication applications. - couple light efficiently form large scale (micro/macroscopic) into nanostructures for practical application. - Model active nanowire devices in order to provide a clear image of light coupling between light generation and light guiding units.
Primary investigators
- Ehsan Jaberansari
- Harold Chong
- Prof. Darren Bagnall
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
semiconductor nanowires offer numerous opportunities for next generation subwavelength optical information processors. As the one dimensional building block element a collection of them can assume different functions in three units of nanoscale photonic circuitry;(i) light generation (active part), (ii) interconnects (passive) and (iii) light detection module. All of these three parts operate on the basis of waveguide principles, although several other issues can affect on the functionality of each individual core. These include coupling, confinement, loss, thermoptics and electrooptics effects, and a number of other material or geometrical concerns. Therefore, this project aims to rigorously investigate and model arbitrary geometric semiconductor nanowire structures fabricated by top-down and bottom-up method, light generation mechanism and perform optical characterization of the nanowires using an integrated near field scanning optical microscope with Raman spectrometer and Laser spectroscopy. All modelling processes are based on commercial software and finite difference time domain algorithm (FDTD) to solve Maxwellââ¬â¢s equations for the desired spatial structure. The semiconductor nanowires of interest are silicon, Silica, zinc oxide, and tantalum pentoxide and heterostructure silicon-germanium. The work is then expanded to more complicated cross sections and functional geometries for various material indices. The results can be then employed as the platform to
-explore the possibility of integrating passive nanowire waveguides with other active photonic and electronic devices in nanoscale for more practical architectures. -invistigate the the applicability of Light modulation techniques in nanowire for computing and communication applications. -couple light efficiently form large scale (micro/macroscopic) into nanostructures for practical application. -Model active nanowire devices in order to provide a clear image of light coupling between light generation and light guiding units.
Primary investigators
- Ehsan Jaberansari
- Dr. Harold Chong
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
- Theme:
- Nanophotonics and Biomimetics
- Funding:
- _other, Department
semiconductor nanowires offer numerous opportunities for next generation subwavelength optical information processors. As the one dimensional building block element a collection of them can assume different functions in three units of nanoscale photonic circuitry;(i) light generation (active part), (ii) interconnects (passive) and (iii) light detection module. All of these three parts operate on the basis of waveguide principles, although several other issues can affect on the functionality of each individual core. These include coupling, confinement, loss, thermoptics and electrooptics effects, and a number of other material or geometrical concerns. Therefore, this project aims to rigorously investigate and model arbitrary geometric semiconductor nanowire structures fabricated by top-down and bottom-up method, light generation mechanism and perform optical characterization of the nanowires using an integrated near field scanning optical microscope with Raman spectrometer and Laser spectroscopy. All modelling processes are based on commercial software and finite difference time domain algorithm (FDTD) to solve Maxwellââ¬â¢s equations for the desired spatial structure. The semiconductor nanowires of interest are silicon, Silica, zinc oxide, and tantalum pentoxide and heterostructure silicon-germanium. The work is then expanded to more complicated cross sections and functional geometries for various material indices. The results can be then employed as the platform to
-explore the possibility of integrating passive nanowire waveguides with other active photonic and electronic devices in nanoscale for more practical architectures. -invistigate the the applicability of Light modulation techniques in nanowire for computing and communication applications. -couple light efficiently form large scale (micro/macroscopic) into nanostructures for practical application. -Model active nanowire devices in order to provide a clear image of light coupling between light generation and light guiding units.
Primary investigators
- Ehsan Jaberansari
- Dr. Harold Chong
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
- Date:
- 2009-2011
- Theme:
- MEMs and NEMs
- Funding:
- EPSRC
The aim of the project is to design, develop and implement an interface based on Sigma-Delta Architecture for Micro-Machined Vibratory Gyroscope. The main idea was to improve the linearity, Dynamic range and Bandwidth. How ever, now the challenge is to reduce the noise effect and improve the accuracy and sensitivity of the interface.
Primary investigator
- Prof. Michael Kraft (mk1)
Partner
- THALES
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
- Date:
- 2009-2011
- Theme:
- MEMs and NEMs
- Funding:
- EPSRC
The aim of the project is to design, develope and implement an interface based on Sigma-Delta Architecture for Micro-Machined Vibratory Gyroscope. The main idea was to improve the linearaty, Dynamic range and Bandwidth. How ever, now the challenge is to reduce the noise effect and improve the accuracy and sensitivity of the interface.
Primary investigator
- Prof. Michael Kraft (mk1)
Partner
- THALES
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre
- Date:
- 2007-2010
- Theme:
- Microfluidics and Lab-on-a-chip
- Funding:
- Department
Dielectrophoresis (DEP), a phenomenon through which non-uniform electric field exerts force on a dielectric particle immersed in a dielectric medium, is one of the most widely-used techniques for manipulating and characterising biological particles in a lab-on-a-chip device. Inaccurate calculation of the DEP force would lead to incorrect modelling of the device or false determination of particle properties. Most, if not all, models in current literature are based on the so-called "dipolar approximation" for making calculation of the DEP force. This approximation accounts only for the first-order force term and ignores all higher-order terms. Theory predicts this approximation to work well only as long as particle dimensions are much smaller than those of the electrode geometry through which the electric field is applied. When the field magnitude varies significantly across the dimensions of the particle, which is a very likely occurrence as electrode geometries shrink in dimensions towards micro-electrode geometries, higher-order force terms are expected to gain increased significance. The same principle applies to torques of electric origin experienced by dielectric particles in lab-on-a-chip devices through the phenomena of electro-rotation (ROT) and electro-orientation (EO).
The preliminary aim of this project is to identify situations where higher-order forces are expected to contribute to a considerable extent to the total DEP force. To accomplish this goal, separate calculations have been made, numerically, of the first three terms of the DEP force, based on the "effective moment method", and of the total DEP force, based on an integration of the Maxwell stress tensor, for particles of different shapes and dimensions subjected to electric fields of varied extents of non-uniformity. Through a comparison of the two sets of results it has been verified that when particle dimensions, be the particles spherical or not, become comparable to a length scale of field non-uniformity, higher-order force terms become increasingly significant such that in some cases they exceed the first-order force term thereby proving the dipolar approximation wrong.
Once instances where higher-order force and torque terms become significant are discovered, the ultimate goal of this project comes into play: to realize an application where higher-order forces and/or torques could dictate particle behaviour in a way that cannot be achieved using a force/torque whose higher-order terms are negligible. One goal in mind is to achieve particle stabilisation through the exertion of higher-order electro-orientational (EO) torques.
Primary investigators
- hn07r
- Nicolas Green
Associated research group
- Nano Research Group
- Date:
- 2007-2010
- Theme:
- Microfluidics and Lab-on-a-chip
- Funding:
- Department
Dielectrophoresis (DEP), a phenomenon through which non-uniform electric field exerts force on a dielectric particle immersed in a dielectric medium, is one of the most widely-used techniques for manipulating and characterising biological particles in a lab-on-a-chip device. Inaccurate calculation of the DEP force would lead to incorrect modelling of the device or false determination of particle properties. Most, if not all, models in current literature are based on the so-called "dipolar approximation" for making calculation of the DEP force. This approximation accounts only for the first-order force term and ignores all higher-order terms. Theory predicts this approximation to work well only as long as particle dimensions are comparable to those of the electrode geometry through which the electric field is applied. When the field magnitude varies significantly across the dimensions of the particle, which is a very likely occurrence as electrode geometries shrink in dimensions towards micro-electrode geometries, higher-order force terms are expected to gain increased significance. The same principle applies to torques of electric origin experienced by dielectric particles in lab-on-a-chip device through the phenomena of electro-rotation (ROT) and electro-orientation (EO). The preliminary aim of this project is to identify situations where higher-order forces are expected to contribute to a considerable extent to the total DEP force. To accomplish this goal, separate calculations have been made, numerically, of the first three terms of the DEP force, based on the "effective moment method", and of the total DEP force, based on an integration of the Maxwell stress tensor, for particles of different shapes and dimensions subjected to electric fields of varied extents of non-uniformity. Through a comparison of the two sets of results it has been verified that there when particle dimensions, be the particles spherical or not, become comparable to a length scale of field non-uniformity, higher-order force terms become increasingly significant such that in some cases they exceed the first-order force term thereby proving the dipolar approximation wrong. Once instances where higher-order force and torque terms are significant are discovered, the ultimate goal of this project comes into play: to realize an application where higher-order forces and/or torques could dictate particle behaviour in a way that cannot be achieved using a force/torque whose higher-order terms are negligible. One goal in mind is to achieve particle stabilisation through the exertion of higher-order electro-orientational (EO) torques.
Primary investigators
- hn07r
- Nicolas Green
Associated research group
- Nano Research Group
- Date:
- 2007-2010
- Theme:
- Microfluidics and Lab-on-a-chip
- Funding:
- Department
Dielectrophoresis (DEP), a phenomenon through which non-uniform electric field exerts force on a dielectric particle immersed in a dielectric medium, is one of the most widely-used techniques for manipulating and characterising biological particles in a lab-on-a-chip device. Inaccurate calculation of the DEP force would lead to incorrect modelling of the device or false determination of particle properties. Most, if not all, models in current literature are based on the so-called "dipolar approximation" for making calculation of the DEP force. This approximation accounts only for the first-order force term and ignores all higher-order terms. Theory predicts this approximation to work well only as long as particle dimensions are comparable to those of the electrode geometry through which the electric field is applied. When the field magnitude varies significantly across the dimensions of the particle, which is a very likely occurrence as electrode geometries shrink in dimensions towards micro-electrode geometries, higher-order force terms are expected to gain increased significance. The same principle applies to torques of electric origin experienced by dielectric particles in lab-on-a-chip device through the phenomena of electro-rotation (ROT) and electro-orientation (EO).
The preliminary aim of this project is to identify situations where higher-order forces are expected to contribute to a considerable extent to the total DEP force. To accomplish this goal, separate calculations have been made, numerically, of the first three terms of the DEP force, based on the "effective moment method", and of the total DEP force, based on an integration of the Maxwell stress tensor, for particles of different shapes and dimensions subjected to electric fields of varied extents of non-uniformity. Through a comparison of the two sets of results it has been verified that there when particle dimensions, be the particles spherical or not, become comparable to a length scale of field non-uniformity, higher-order force terms become increasingly significant such that in some cases they exceed the first-order force term thereby proving the dipolar approximation wrong.
Once instances where higher-order force and torque terms are significant are discovered, the ultimate goal of this project comes into play: to realize an application where higher-order forces and/or torques could dictate particle behaviour in a way that cannot be achieved using a force/torque whose higher-order terms are negligible. One goal in mind is to achieve particle stabilisation through the exertion of higher-order electro-orientational (EO) torques.
Primary investigators
- hn07r
- Nicolas Green
Associated research group
- Nano Research Group
- Date:
- 2008-2011
- Theme:
- Microfluidics and Lab-on-a-chip
- Funding:
- EPSRC
My main research area in interest on RMST project is ââ¬ËMicro-fluidic and Lab on a chip Technologyââ¬â¢. I am concentrating on the research for the development of technologies involves fabrication of micro-structure (micro-electrodes) and micro-fluidic polymeric devices. In addition, I am also concentrating on technologies for hot embossing process (HE) on polymers (e.g. COC, COP, PMMA etc) for creating micro-fluid structure and aligned bonding techniques to seal micro-devices.High aspect ratio silicon (Si) mould master is fabricated with micro-fluidic structure using deep reactive ion etched technique (DRIE) to create Ni master using electro-form technique to emboss microfluidic structure on polemers.
Figure 1 shows a Si mould master with micro-fluidic structure. This mould is used for Ni electro-plating. Figure 2 shows a embossed micro-fluidic channel on zeonox 690R COC (Tg 136ðC )using Ni stamp.
Primary investigators
- Prof Hywel Morgan
- Dr Matt Mowlem
Secondary investigator
- Dr Shahanara Banu
Partner
- ââ¬Â¢National Oceanography Centre (Sensors group)
Associated research groups
- Nano Research Group
- Southampton Nanofabrication Centre