title: Microfabrication procedure of PDMS microbeam array using photolithography for laminin printing and piconewton force transduction on axons.
abstract: The purpose of this paper is to introduce our design for transducing forces on the order of tens of piconewtons by optically measuring deflection of a microfabricated beam tip as it pulls on an array of flexible structures such as axons in an array of laminin-printed neurons. To achieve this we have designed polymeric beams with spring constants on the order of 10 pN/microm. We have fabricated circular microbeams with Sylgard polydimethylsiloxane (PDMS). The elastic modulus of PDMS was determined experimentally using a microscale and a micrometer at different concentrations of curing agent and base agent and found to be on the order of 100 kPa. The designed geometry is a 100x100 tapered microcone array with each beam having a length of 100 microm, and a base diameter of 10 microm. A SU-8 negative photoresist is etched using photolithography and used as a mold for PDMS soft lithography. PDMS was injected into the mold and the array peeled from the mold.
authors.affiliation: Drexel University, Philadelphia, PA 19104, USA.
authors.forename: F Mert
authors.initials: FM
authors.lastname: Sasoglu
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Bohl
authors.forename: Bradley E
authors.initials: BE
authors.lastname: Layton
mesh_terms: D001369:Axons / Q000502:physiology*; D001672:Biocompatible Materials / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007797:Laminin / Q000737:chemistry*; D008365:Manometry / Q000295:instrumentation* / Q000379:methods; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D046228:Microarray Analysis / Q000295:instrumentation*; D008904:Miniaturization; D009757:Nylons / Q000737:chemistry*; D010781:Photography / Q000379:methods*; D013314:Stress, Mechanical; D014159:Transducers
chemical_list: D001672:Biocompatible Materials; D004129:Dimethylpolysiloxanes; D007797:Laminin; D009757:Nylons; C085707:poly(dimethylsiloxane)-polyamide copolymer