Design and analysis of novel MEMS cantilever biosensor with special focus on SCR for tuberculosis detection

In this paper, the MEMS cantilever beam bio-sensing system is simulated, analyzed and designed for quick tuberculosis detection using Intellisuite Software. The surface of the cantilever has been coated with antibodies, which bind to the antigen present. The surface is strained and forms deflection once the target molecules are discovered. A variety of models were designed from different materials with varying lengths, widths and shapes of the cantilever to improve displacement and sensitivity. To improve the performance of the cantilever, stress concentrating region (SCR) designs is included. Materials analyzed in this paper were silicon, gold, polydimethylsiloxane (PDMS) and polyimide. The highest displacement achieved \(4.59\times 10^{-2}\,\upmu \text{m}\) $4.59\times {10}^{-2}\mathrm{\mu }\text{m}$ with PDMS material for length \(300\,\upmu \text{m},\) $300\mathrm{\mu }\text{m},$ width \(50\,\upmu \text{m}\) $50\mathrm{\mu }\text{m}$ and thickness \(0.5\,\upmu \text{m}.\) $0.5\mathrm{\mu }\text{m}.$ Improved displacement achieved \(9.30\times 10^{-2}\,\upmu \text{m}\) $9.30\times {10}^{-2}\mathrm{\mu }\text{m}$ with PDMS using SCR model-2 for length \(300\,\upmu \text{m},\) $300\mathrm{\mu }\text{m},$ width \(50\,\upmu \text{m}\) $50\mathrm{\mu }\text{m}$ and thickness \(0.5\,\upmu \text{m}.\) $0.5\mathrm{\mu }\text{m}.$ Among shape variants, T-shaped is found to achieve the highest displacement. For limited size and compact design biosensors modified improved model is designed with a combination of SCR model-2 and T-shaped with length \(200\,\upmu \text{m}\) $200\mathrm{\mu }\text{m}$ which produces the highest displacement of \(5.44\times 10^{-2}\,\upmu \text{m}.\) $5.44\times {10}^{-2}\mathrm{\mu }\text{m}.$ The readout method for biosensor design is done in MATLAB Simulink. Piezoelectric material Lead Zirconate Titanate (PZT-5A) is also used to provide an output voltage. PDMS is discovered the highest displacement and voltage among the other three materials.