Visible light maskless photolithography for biomachining application

Maskless photolithograpy is an alternative method of conventional UV photolithograpy for microfabrication since its advantages of time and cost saving. For this reason, a visible-light based maskless photolithograpy is proposed as a part of biomachining process. Modification of the method is done by replacing light source of UV light to visible light, utilizing commercial DLP projector and changing the material removal process that generally uses echant with biomachining process. The process was done by using the profile generated by computer then displayed through a commercial DLP projector shining speciment test. Focusing lens placed under the projector to draw the focal point and reduces the size of the profile. The best parameter was determined by setring exposure time, developing time, variation profiles, focusing, colors combination and optical aspect. Using a commercial projector maskless photolithography on a negative resist tone successfully performed. The best characteristic was obtained by placing the focusing lens 3X magnification within 3 cm below the projector and 14 cm above speciment test, color combination of black-light blue (R = 0, G = 176, B = 240), with the timing of prebake 1 minute, exposure 7 minutes, postbake 5 minutes, developing 5 minutes produces the smallest profile 166 μm with 13,7 μm deviation. Biomachining process with bacteria Acidithiobacillus ferrooxidans NBRC 14262 on copper was also successfully performed with the smallest profile of 180 μm with 26 μm deviation.