Free-Form Polymeric Micro Lens Array Molded By Electrostatic Force Deformed Template

This paper introduced a new method to fabricate a free-form micro lens array. A conductive template was deformed by applied voltage on its underneath electrodes, and polymer primer was poured in this template to form a micro lens array after curing and de-molding process. A integrate simulation process of the micro lens array was proposed. The geometry of the template at a certain bias was figured out through multiple physical field simulation. Next, a three dimensional solid body was generated by surrounding the deformed surface of the template with a flat surface. Finally, This solid body was input into an optical lens simulation environment to obtain its optical performance. As a demonstration, a PDMS free-form micro lens array was designed and fabricated using this Molding by Electrostatic Force Deformed Template (MEFDT) method successfully. Metal electrodes layer, SU-8 layer and conductive membrane layer were deposited and patterned in sequence to realize the template, and then PDMS micro lens array was duplicated using this template with an applied voltage. Through changing the initial shape of the template as well as the position and bias of the electrodes, this MEFDT method is believed to have the ability to achieve micrometer size lens with precisely controlled geometry.