Humidity influence on the adhesion of SU-8 polymer from MEMS applications

Abstract

Abstract. In this paper, the adhesion behaviors of SU-8 polymer thin film from MEMS application were investigated as a function of relative humidity. The adhesion test between the AFM tip and SU-8 polymer have been extensively studied using the atomic force microscope (AFM), for a relative humidity (RH) varying between 20 and 90%. The samples for tests are SU-8 polymers hard baked at different temperatures. The hard bake temperature changes the tribo-mechanical properties of polymers. The paper reports the measurements and the modeling of adhesion forces versus humidity in controlled ranges between 20 to 90%RH. To investigate the effect of relative humidity on adhesion for SU-8 polymer hard baked we used an analytical method which encompasses the effect of capillarity as well as the solid-to-solid interaction. While the capillary force expression is considered to be the sum of the superficial tension and the Laplace force for the solid-solid interaction is expressed by the Derjagin, Muller and Toropov (DMT) model of solids adhesion. The analytical results obtained are in accordance with those obtained experimentally.

3D Generation of Multipurpose Atomic Force Microscopy Tips

“…[ 33 ] While for SU8‐silicon interaction, these values are reported to be 0.65 × 10 –20 J in air and 0.18 × 10 –20 J in water. [ 34 ] Thus, with the latter Hamaker being ≈26 times smaller in air and ≈30 times smaller in water, the magnitude of the van der Waals interactions is also significantly less with the 3DTIPs, which makes them prone to screening and overshadowing by other forces rising from the tip‐sample environment, such as air, liquid, and humidity.…”

Integrating Electronic Components into 3D Printed Parts to Develop a Digital Manufacturing Approach

“…In this method, some channels are left intentionally hollow in the part, and after manufacturing, they are filled with conductive ink. In this manner, interesting components such as micro-electro-mechanical-systems (MEMS) could be developed [22]. Using this technique, we produce integrated paths in the 3D printed sample, which can be used for actuating, in this case, thermal regulation, or even sensing purposes.…”