Introduction to Microsystems – the first class

Macro Micro Nano Meso (100 nm to 1 um) Microsystem or MEMS has the overall size of a device less than 100 um. Meso scale: 100 um to mm. Macro scale: larger than 1 mm. 1 nm = 1000 um. To any system, our concern lies in: Fabrication (make or construct). Architecture, structure and behavior. Principles. Both marco-device and micro-device share the same governing principles in physics and chemistry and biology. But nano-devices have different governing principles from the macro-devices or micro-devices. Macro Micro Nano Meso (100 nm to 1 um)

Microsystems change the architecture of a device (micro-device), as opposed to the architecture of a macro-device, due to the limitation of the fabrication technology for macro-devices. The nature of fabrication means for macro-system is: (1) making components and (2) assemble components into a product. The macro-fabrication technology is not suitable to operating on the component in less than 100 um. The micro-fabrication technology has its distinct feature, and this distinct feature causes the change of the device architecture.

The feature of micro-fabrication technology is: (1) making a 2D entity and (2) grow on the 2D entity. Deposition In-plane Out-plane Suspending structure is made by material removal after deposition. Suspending structure or hollow structure may also be made by molding and bonding http://www.3me.tudelft.nl/uploads/media/SEM_image_of_suspended_SiO2_structure_consisting_of_four_beams__connected_at_their_free_ends.jpg

Making a 2D device (in the x-y plane). Making a 3D device in the Z-axis. Making a 2D device in the micro-meter scale  microelectronic products fabrication  lithography-based fabrication technique The scope of materials suitable for lithography process The scope of materials suitable for making electronic elements Semi-conductor material Beam-sensitive material (beam: light beam, electrons beam, etc.)

Remark Microsystems may not be based on mechanical and electrical elements only, though MEMS does imply this point. Mechanical system: motion, which then involves inertia, damping, and stiffness. Motion can be made by having an articulate joint for two components or producing a deformation of a component. Mechanical work (Joint motion and deformation motion along with force or moment) are generated by another form of energy which can be: electrical energy, thermal energy, light energy, etc. This means that Microsystems go beyond MEMS.

Heating  deformation: thermal mechanical system: an example