We present a noval method of 3D microfabrication with LIGA process that utilizes a deep X-ray mask in which a microactuator is integrated. The integrated micro-actuator oscillates the X-ray absorber, which is formed on the shuttle mass of the micro-actuator, during X-ray exposures to modify that absorbed dose profile in X-ray resist, typically PMMA. 3D PMMA microstructures according to the modulated dose controur are revealed after GG development. An X-ray mask with integrated comb drive actuator is fabricated using deep reactive ion etching, absorber electroplating, and bulk micromachining with silicon-on-insulator wafer. 1 mm × 1 mm, 20 μm thick silicon shuttle mass as a mask blank is supported by four 1 mm long suspesnsion beams and is driven by the comb electrodes. A 10 μm thick, 50 μm line and spaced gold absorber pattern is electroplated on the shuttle mass before the release step. The fundamental frequency and arnplitured are around 3.6 kHz and 20 μm, respectively, for a dc bias of 100 V and an ac bias of 20 VP-P (peak-peak). Fabricated PMMA microstructure shows 15.4 μm deep, S-shaped cross section in the case of 1.6 kJ cm−3 surface dose and GG development at 35°C for 40 minutes.
Synthesis of hollow and spherical cadmium sulphide nanoparticles by an unconventional design of bioelectrochemical system