Design and validation of an instrumented electrospinning system for nanofiber deposition on semiconducting substrates: a case study using SU-8 and CNT/SU-8 composites

Abstract Electrospinning enables the fabrication of polymer nanofibers with tunable morphological and functional properties; however, its application to semiconducting substrates presents technical challenges due to limited control over deposition parameters and poor charge dissipation. In this work, we report the design, instrumentation, and validation of a custom electrospinning system developed to address these challenges. The system integrates modular hardware and software components for precise, reproducible control over applied voltage, flow rate, and needle-to-collector distance. Environmental conditions (temperature and humidity) are also monitored in real time to improve consistency in fiber formation. To evaluate system performance, we employed a novolac-based epoxy photoresist (SU-8) and carbon nanotube-reinforced SU-8 composite solutions as case study materials, both known for their electrospinning difficulty yet offering high relevance for microfabrication applications. Process optimization enabled the direct deposition of uniform nanofiber mats on silicon substrates, eliminating transfer steps and reducing contamination risks. Additives such as poly(ethylene oxide) and tri-tert-butylphosphonium tetrafluoroborate (BF₄) further improved fiber uniformity and mat density. Comprehensive characterization was conducted to validate deposition quality and post-processing outcomes. Scanning electron microscopy and Raman spectroscopy were used to assess nanofiber morphology, mat coverage, and microstructure, while rheological analysis quantified the viscoelastic properties of the precursor solutions. This instrumented electrospinning platform offers a reproducible and scalable route for nanofiber integration in carbon-based microdevices. Its modular and compact design makes it well suited for research environments focused on Carbon Microelectromechanical Systems, biomedical devices, and microscale energy storage technologies, expanding the capabilities of electrospinning in advanced manufacturing.