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Many decades have seen the exploration of a novel methodology for developing microstructure in Microfluidic devices. Despite many methodologies, femtosecond laser technique has been a rising method in the conspicuous way of developing microstructures through direct write method which provides an ease of fabrication. For fabrication precise microstructure in semiconductor devices such as silicon, the femtosecond laser is preferred. An array of micro-holes has been created in monocrystalline silicon (100) using femtosecond laser ablation with multiple pulses. An investigation is carried out for obtaining the minimum diameter holes by varying the power for multiple pulses. The fabricated microhole array find its application in cancer cell separation from human blood. [ABSTRACT FROM AUTHOR]

Isolation of circulating tumor cells from human blood plays a significant role in diagnosis and treatment of cancer. The most effective way of isolating cells is the use of lab on-chip microfluidic devices. This paper presents the development of cyclic olefin polymer membrane with an array of micropores for separating circulating tumour cells using ultrashort laser ablation process. Initially, the substrate is tested for its cell viability. The laser Fluence is varied from 1–12 J/cm2 and its observed that at a fluence of 2.5 J/cm2 the desired diameter of 12 μm with ablation depth of 1 μm is obtained which is necessary for CTC separation. The treated and untreated structure is characterized using Fourier transform infrared spectrometer and it shows that the treated region shows no significant shift in the spectrum after femtosecond laser ablation. [ABSTRACT FROM AUTHOR]

Design, fabrication and characterization of a novel RF switch is proposed in this paper. The multiport RF MEMS switch provides a single input multiple output novel topology suitable for satellite payload applications. A single ETA is used to switch the device from one mode to another. When a voltage difference is applied across the electrode pads of ETA, and depending on the configuration, the actuator actuates forward or backward in plane producing either a quad or dual output respectively. The reflection loss and insertion loss are improved effectively. Measurement results show that in `dual mode’ position, the input reflection coefficient (S11) is less than − 50 dB with the forward transmission coefficient (S21) better than − 2 dB at 0-15 GHz. At ‘quad mode’, position, the input reflection coefficient (S11) is less than − 55 dB with the forward transmission coefficient (S21) better than − 4 dB at 0-15 GHz. The larger than 50 dB over 0-15 GHz isolation realized in both modes of operation ensures dual and quad mode outputs without information loss. The actuation voltage is reduced to 4.5 V. The measured power handling capability can reach up to 35 dBm while the power consumption of the switch is 50 mW. This compact RF MEMS capacitive switch possesses excellent performances in terms of low insertion loss, high isolation, low power and high power handling capability. [ABSTRACT FROM AUTHOR]

Fabrication and characterization of a novel bistable MEMS (MicroElectroMechanical Systems)-based switch is reported in this paper. The bistable switch is fabricated on SOI wafer with 10 µm thick device Si layer using Silicon-On-Insulator Multi User MEMS Process with three masks. The proposed device is comprised of a centrally clamped parallel curved beams (switching element) and a pair of electrothermal V-beam microactuators (actuating element). The bistability is achieved through the buckling of centrally clamped parallel curved beams and the critical buckling load is provided by the electro-thermal expansion of the V-beam microactuators. Hinges, latches, membranes are not used in the proposed design and thus the fabrication complexity is reduced to a greater extent. A maximum displacement of 20.7 µm is achieved at 14 V DC supply for the V-beam microactuator and this thermal expansion of the V-beam microactuator acted as the critical buckling load for the centrally clamped parallel curved beam. Electrical and mechanical characterization of switch is performed and after the analysis, it is verified that the nonlinear property (elasticity) of silicon material is poor and that is the reason for comparatively higher actuation voltage to simulation results. A novel optimized redesign for the electrothermal V-beam microactuator based on POLYMUMPs process is proposed in order to overcome the uncertainties endured. [ABSTRACT FROM AUTHOR]

A new array type cantilever structure with improved bandwidth and enhanced power output is proposed in this paper. Instead of having a normal rectangular end, the proposed cantilever will have triangular end with proof mass which will increase the power output and further the power is improved by having an array structure. In the array of cantilever, each structure will be having different proof mass so that the frequency with which they vibrate will differ. By using this new array structure of cantilever, bandwidth of 39 Hz and power of 7 µW is generated for rectangular end and bandwidth of 48 Hz and power of 8 µW is generated for triangular end. [ABSTRACT FROM AUTHOR]