Ni-P-CNTs nanocomposite film for MEMS applications

A Ni-P-CNTs (electroless phosphorus nickel-carbon nanotubes) nanocomposite film synthesis and related processes for MEMS device fabrication have been successfully developed and presented in this paper. With a special acid oxidative method, a well-dispersed nickel-CNTs colloidal solution has been produced without any aggregation, very suitable for microstructure fabrication. The nano-indentation measurement indicates that the Young's modulus and hardness of the Ni-P-CNTs nanocomposite film plated in the bath with 0.028 g/L CNTs can greatly increase up to 666 Pa and 29 GPa, respectively, which is four times larger than that of pure nickel. The performance improvement of the electro-thermal microactuator made of the nanocomposite, including device strength and power efficient, have been proved similar to the Ni-diamond composites. With the same power input, the device can provide 4 times elongation longer than that made of pure nickel. The mechanical strength of the actuator can also be enhanced to sustain the input power with two times larger than the pure one.