Sublimation technique for minimization of stiction induced during fabrication of closely spaced microstructures

• Published in: Advances in materials and processing technologies (Abingdon, England) Vol. 8; no. 4; pp. 3889 - 3899
• Main Authors: S. Bhole, Kiran, Kale, Bharatbhushan
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 02.10.2022
• Subjects: MEMS; micro-stereolithography; microfabrication; Stiction effect; sublimation drying
• ISSN: 2374-068X; 2374-0698
• DOI: 10.1080/2374068X.2022.2036445

Stiction effect during post-processing of the polymer-based microelectro mechanical systems (MEMS) is a major class of failure in which two arrayed microstructures adhere together. This stiction can be avoided by lowering the surface energy. One of the ways to have low surface energy is to have a mechanism of sublimation of solvent while releasing the microstructures. This paper presents the development of a sublimation technique for minimisation of the stiction effect, which gets induced between closely spaced microstructures. Solvent t-butyl alcohol is used as an enabler in the sublimation drying technique. Vacuum Pump for generation of low pressure for sublimation, Peltier chips acting as solid-state refrigerator and measurement systems like vacuum gauge and thermocouple are used in the developed system. This design of the system has laid generalised pathways for the development of the sublimation-based drying and releasing technique. To validate the concept of the process, test experiments are conducted on naturally available microfeatures (bird's feather). The test experiments have shown the promise of releasing the microstructures without stiction. The proposed design is expected to open new avenues for post-processing of the microarrayed structures.