The rapidly emerging field of MEMS (micro electromechanical systems) has recently seen a proliferation of microscale devices and processes. Indeed, microsystems and nanotechnology has from its origins in the integrated circuits industry now become an extensive field of research encompassing everything from biosensors with near real-time diagnostics to power MEMS for portable devices, enabling vastly improved performance to power consumption over their macro counterparts. The paper uses relevant contemporary issues that arise from conceptual limitations in this burgeoning field to illustrate and highlight some critical analysis of the key educational issues involved in teaching in this vital area. The paper considers a number of political-strategic issues arising for Ireland directly out of the nano-biotechnology revolution. It also highlights a number of relevant concerns that can be addressed by educational initiatives. Theoretical and philosophical concepts regarding changes in thinking surrounding recent developments are also explored, with some specific primary science discussion made on research issues and second-third level education. The paper ends with an attempt to identify the major opportunities for Ireland and highlights the changes that science and technology will wrote for an Ireland ready or not, to face a new reality that is also no respecter of any country's past successes.
This paper describes an innovative excimer laser fabrication approach for profiling optimally smooth airflow contours. The research merit of the process is its use in producing a new type of electrical transducer micro-turbine using a novel axial format. The necessary micro-machining precision for this was achieved by computer-controlling a laser beam using an elevating stage to step a moving mask across a fixed mask, i.e. a variant of dynamic mask-dragging or mask-aperturing. The moving mask image was projected on to a series of flat 600 μm wide, 1000 μm deep preform surfaces, reducing each to 50 μm thickness with curvature. Precise control of each mask increment to ablation depth and focus allowed a range of 3-D curves to be realized. The ablation rate versus surface quality was optimized throughout by ablating just 300 nm per laser pulse and using 2000 pulses spread over 90 sites. The process represents a cost effective means of using basic masks to continuously shape flat surfaces in the axial direction with high aspect ratios, high speed and precision, and is applicable to both micro streamlining and the manufacture of micro expansion nozzles.
We have used KrF excimer laser ablation in the fabrication of a novel MEMS power conversion device based on an axial-flow turbine with an integral axial-flux electromagnetic generator. The device has a sandwich structure, comprising a pair of silicon stators either side of an SU8 polymer rotor. The curved turbine rotor blades were fabricated by projection ablation of SU8 parts performed by conventional UV lithography. A variable aperture mask, implemented by stepping a moving aperture in front of a fixed one, was used to achieve the desired spatial variation in the ablated depth. An automatic process was set up on a commercial laser workstation, with the laser firing and mask motion being controlled by computer. High quality SU8 rotor parts with diameters of 13 mm and depths of 1 mm were produced at a fluence of 0.7 J/cm2, corresponding to a material removal rate of approximately 0.3 μm per pulse. A similar approach was used to form SU8 guide vane inserts for the stators.