| 1. |
- Claesson, Åsa, et al.
(författare)
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Novel design for diode-pumped miniature lasers using microstructured silicon carriers
- 2000
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Ingår i: Advanced Solid State Lasers. - : Optica Publishing Group.
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Konferensbidrag (refereegranskat)abstract
- A new design concept for compact diode-pumped solid-state lasers is presented. The design is based on a microstructured silicon carrier with etched v-grooves. This silicon microbench provides efficient thermal management at 10W pumping level, as well as compact integration and alignment of all active and passive optical components of compact diode-pumped solid-state lasers. In initial experiments, a Nd:YAG laser built on the microbench delivered a continuous-wave output of 3W.
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| 2. |
- Ek, Patrik, et al.
(författare)
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Electrospray Ionization from an Adjustable Gap between two Silicon Chips
- 2009
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Ingår i: Journal of Mass Spectrometry. - : Wiley. - 1076-5174 .- 1096-9888. ; 44:2, s. 171-181
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a silicon chip - based electrospray emitter with a variable orifice size is presented. The device consists of two chips, with a thin beam elevating from the center of each of the chips. The chips are individually mounted to form an open gap of a narrow, uniform width between the top areas of the beams. The electrospray is generated at the endpoint of the gap, where the spray point is formed by the very sharp intersection between the crystal planes of the < 100 > silicon chips. Sample solution is applied to the rear end of the gap from a capillary via a liquid bridge, and capillary forces ensure a spontaneous imbibition of the gap. The sample solution is confined to the gap by means of a hydrophobic treatment of the surfaces surrounding the gap, as well as the geometrical boundaries formed by the edges of the gap walls. The gap width could be adjusted between 1 and 25 μm during electrospray experiments without suffering from any interruption of the electrospray process. Using a peptide sample solution, a shift toward higher charge states and increased signal-to-noise ratios was observed when the gap width was decreased. The limit of detection for the peptide insulin (chain B, oxidized) was approximately 4 nM. We also show a successful interfacing of the electrospray setup with capillary electrophoresis.
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| 3. |
- Khalifa, Shaden Ali M., et al.
(författare)
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Guidance of spiral ganglion neurons over 3 mm using protein patterned surfaces in Co-culture
- 2014
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Ingår i: Tissue Engineering and Regenerative Medicine. - : Kluwer Academic Publishers. - 1738-2696 .- 2212-5469. ; 11:3, s. 187-194
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Tidskriftsartikel (refereegranskat)abstract
- Despite considerable advances in neural prosthetics there are still few clinical devices capable of effectively compensating for the loss of a physiological function. By far the most successful to date are cochlear implants, which can restore the auditory function in patients with severe sensorineural impairment. These implants have electrode arrays that directly stimulate the remaining neurons and several strategies are applied to encourage neurons to interact intimately with the electrodes. Integration of the residual neurons into the circuits can be aided by appropriate micro-patterning on the electrodes' surfaces to guide the regenerating neurons. Here we describe experiments revealing key features of the interface between auditory cell cultures and surface patterning. In the presented study linear regenerative outgrowth of spiral ganglion axons occurred over distances of several hundred micrometers in the presence of extracellular protein cues placed precisely on surfaces by micro-contact printing. The protein pattern guided the outgrowth of spiral ganglion neurons along interconnected networks of non-neuronal cells. High-precision alignment of axons with no branching or deviation was influenced by, but not dependent upon, the presence of non-glial cells. The findings show that micro-patterning provides a versatile, robust system that can not only guide the outgrowth of individual neurons but also regulate the orientation of diverse cell types in culture. © 2014 The Korean Tissue Engineering and Regenerative Medicine Society and Springer Science+Business Media Dordrecht.
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| 4. |
- Khalifa, Shaden Ali M., et al.
(författare)
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Neuronal polarity mediated by micro-scale protein patterns and schwann cells in vitro
- 2013
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Ingår i: Tissue Engineering and Regenerative Medicine. - : Kluwer Academic Publishers. - 1738-2696 .- 2212-5469. ; 10:5, s. 266-272
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Tidskriftsartikel (refereegranskat)abstract
- Implantable electrical devices have been in use over decades to restore vital functions. Among the wellknown devices are pace makers for regulating heart rate, neurostimulators for treating neurological disorders, and cochlear implants for rescuing the hearing organ. The cochlear implant is used for patients with severe neuro-sensory hearing loss. The implant consists of an electrode that provides electrical stimuli to the spiral ganglion neurons in the cochlea, thus eliciting impulses in the pathways that normally convey auditory information from the hearing organ to the brainstem. However, disorganization of the residual spiral ganglion collaterals within and around the same frequency region of the electrode can lead to non-specific signaling and thereafter inability to discriminate the sounds. A situation that can limit considerably the maximum recovery of the auditory function after cochlear implantation. Thus, strategies that promote functional mimicry in close vicinity of the electrode are considered as potential solutions. The strict bipolarity of sensory neurons is a unique micro anatomical peculiarity of the inner ear innervations and may constitute a new option to improve sound perception within localized frequency range. In this paper, we show that minimal guidance cues provided via a simple printing technique using patterns soaked with proteins are enough to modify profoundly the polarity of regenerating spiral ganglion neurons. Regenerating spiral ganglion neurons preferentially acquired uni- or bi-polar morphology with limited branching on alternating lines structured surfaces. The neuronal processes grow in a direction parallel to the lines for distances that exceeds 2 mm.
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| 5. |
- Kvisteroy, Terje, et al.
(författare)
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Far infrared low-cost uncooled bolometer for automotive use
- 2007
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Ingår i: Advanced Microsystems for Automotive Applications 2007. - BERLIN : SPRINGER-VERLAG BERLIN. - 9783540713241 ; , s. 265-278
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Konferensbidrag (refereegranskat)abstract
- A proposed EU regulation requires the automotive industry to develop technologies that will substantially decrease the risk for vulnerable road users such as pedestrians when hit by a vehicle. Automatic brake assist systems, activated by a suitable sensor, will reduce the speed of the vehicle before the impact. Far InfraRed (FIR) detectors are ideal candidates for such sensing systems. In order to enable high volume serial installation, the main development must be focused on cost reduction. Optimizing all aspects of the system, including sensor size, production yield and 3D wafer level vacuum packaging will lower today's "high end" FIR product costs by an order of magnitude. A low-cost FIR infrared bolometer is developed in the Eureka labeled PIMS (Pedestrian Injury Mitigation System) project. In the paper the background and the actual design of the first demonstrator to be finished in 2008 are described in detail.
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| 6. |
- Källhammer, Jan-Erik, et al.
(författare)
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Fulfilling the pedestrian protection directive using a long-wavelength infrared camera designed to meet both performance and cost targets
- 2006
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Ingår i: Photonics in the Automobile II. - : SPIE. ; , s. 19809-19809
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Konferensbidrag (refereegranskat)abstract
- Pedestrian fatalities are around 15% of the traffic fatalities in Europe. A proposed EU regulation requires the automotive industry to develop technologies that will substantially decrease the risk for Vulnerable Road Users when hit by a vehicle. Automatic Brake Assist systems, activated by a suitable sensor, will reduce the speed of the vehicle before the impact, independent of any driver interaction. Long Wavelength Infrared technology is an ideal candidate for such sensors, but requires a significant cost reduction. The target necessary for automotive serial applications are well below the cost of systems available today. Uncooled bolometer arrays are the most mature technology for Long Wave Infrared with low-cost potential. Analyses show that sensor size and production yield along with vacuum packaging and the optical components are the main cost drivers. A project has been started to design a new Long Wave Infrared system with a ten times cost reduction potential, optimized for the pedestrian protection requirement. It will take advantage of the progress in Micro Electro-Mechanical Systems and Long Wave Infrared optics to keep the cost down. Deployable and pre-impact braking systems can become effective alternatives to passive impact protection systems solutions fulfilling the EU pedestrian protection regulation. Low-cost Long Wave Infrared sensors will be an important enabler to make such systems cost competitive, allowing high market penetration.
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| 7. |
- Kälvesten, Edvard, 1967, et al.
(författare)
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An Integrated Pressure-Velocity Sensor for Correlation Measurements in Turbulent Gas Flows
- 1996
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Ingår i: Sensors and Actuators A. ; :52, s. 51-58
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Tidskriftsartikel (refereegranskat)abstract
- A new integrated pressure—flow sensor has been specially designed for measurements in turbulent gas flows. The pressure sensor is based on polysilicon diaphragm technology and the flow sensor on the gas cooling of a polyimide-insulated heated mass. With a pressure-sensor diaphragm area of 100 μm × 100 μm, a flow-sensor hot-chip area of 300 μm × 60 μm and an edge-to-edge distance of 100 μm between the different sensor areas, the smallest eddies in technically interesting turbulent flows can be resolved and measured. The pressure-sensor design shows a flat frequency response curve within ±2 dB between 10 Hz and 10 kHz with an acoustic sensitivity of 0.9 μV Pa−1 for a supply voltage of 10 V. The flow sensor has a thermal response with a time constant of 7 ms and a response time of 25 μs when the sensor is operated at constant temperature using feedback electronics. The measured steady-state flow-sensor power dissipation in a turbulent wall boundary layer at an overtemperature of 100 °C was P = 34 + 0.4τ00.47 mW where τ0 is the time-average flow-dependent wall shear stress. The integrated sensor has been used for simultaneous measurement of fluctuating pressure and wall shear stress in a turbulent boundary layer yielding pressure—wall shear stress correlation coefficients never previously presented.
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| 8. |
- Kälvesten, Edvard, 1967, et al.
(författare)
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An Integrated Pressure-Velocity Sensor for Correlation Measurements in Turbulent Gas Flows
- 1995
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Ingår i: Transducers´95- Eurosensors 9, Stockholm.
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Konferensbidrag (refereegranskat)abstract
- A new integrated pressure-flow sensor has been specially designed for measurements in turbulent gas flows. The pressure sensor is based on polysilicon diaphragm technology and the flow sensor on the gas cooling of a polymide-insulated heated mass. With a pressure-sensor diaphragm area of 100 μm x 100 μm, a flow-sensor hot-chip area of 300 μm x 60 μm and an edge-to-edge distance of 100 μm between the different sensor areas, the smallest eddies in technically interesting turbulent flows can be resolved and measured. The pressure-sensor design shows a flat frequency response curve within ___ 2dB between 10 Hz and 10 kHz with an acoustic sensitivity of ___ for a supply voltage of 10 V. The flow sensor has a thermal response with a time constant of 7 ms and a response time of 25 μs when the sensor is operated at constant temperature using feedback electronics. The measured steady-state flow-sensor power dissipation in a turbulent wall boundary layer at an overtemperature of 100 degrees Celsius was ___ mW where ___ is the time-average flow-dependant wall shear stress. The integrated sensor has been used for simultaneous measurements of fluctuating pressure and wall shear stress in a turbulent boundary layer yielding pressure-wall shear stress correlation coefficients never previously presented.
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| 9. |
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| 10. |
- Niklaus, Frank, et al.
(författare)
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MEMS-Based uncooled infrared bolometer Arrays : A review
- 2008
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Ingår i: P SOC PHOTO-OPT INSTRUM ENG. - : SPIE. - 9780819470119 ; , s. D8360-D8360
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Konferensbidrag (refereegranskat)abstract
- Uncooled infrared bolometer arrays have become the technology of choice for low-cost infrared imaging systems used in applications such as thermography, firefighting, driver night vision, security and surveillance. Uncooled infrared bolometer arrays are reaching performance levels which previously only were possible with cooled infrared photon detectors. With a continuously increasing market volume (> 100 000 units per year to date), the cost for uncooled infrared imaging chips are decreasing accordingly. In this paper we give an overview of the historical development of uncooled infrared bolometer technology and present the most important bolometer performance parameters. The different technology concepts, bolometer design approaches and bolometer materials (including vanadium oxide, amorphous silicon, silicon diodes, silicon-germanium and metals) are discussed in detail. This is followed by an analysis of the current state-of-the-art infrared bolometer technologies, the status of the infrared industry and the latest technology trends.
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