Thermogravimetric Analysis on a Resonant Microcantilever

Abstract

Thermogravimetric analysis (TGA) is a widely applied classic method for material characterization. However, the existing TGA method has reached its technical ceiling in regard to its sensitivity, efficiency, application scope, and extensibility. With temperature-programming and a picogram (10-12 g) mass resoluble measurement function, an integrated resonant microcantilever is proposed and developed into micro-electromechanical system-based TGA (MEMS TGA) technology to satisfy the significantly higher TGA requirements. With only a nanogram (10-9 g) level of a loaded sample, the microcantilever can conduct ultrasensitive mass-loss analysis along with ultrafast and controllable heating up to 1200 °C. Experiments have verified that MEMS TGA can improve heating efficiency by at least one order of magnitude compared to conventional TGA while maintaining measurement accuracy. The trace sample requirement also enables MEMS TGA to directly test explosive substances in an air atmosphere, while conventional TGA with a larger amount of sample has difficulty in avoiding explosion-induced equipment damage during heating. The silicon MEMS TGA microchip also exhibits functional combination (even integration) with other analytical techniques such as Raman spectroscopy to realize operando characterization.