Search Results (2)

This paper presents a theoretical and experimental investigation of the amplitude–frequency response of a triple-microcantilever system designed for real-time ultra-low mass detection. The present study focuses on the unfunctionalized configuration to clarify the intrinsic electromechanical behavior of this system. Starting with analytical expressions, output voltage amplitude–frequency responses are derived for a Wheatstone-bridge-based readout circuit and used to analyze the relationship between the resonant frequencies and mechanical amplitude–frequency responses of the three microcantilevers and the resulting electrical response. The extrema and zero-crossing points of the output voltage do not trivially coincide with the individual resonance peaks or their intersection points; this offers more freedom for defining strong detection criteria. A specialized experimental setup has been developed and used to measure the frequency response of a fabricated triple-microcantilever prototype; good agreement with the theoretical predictions has been found within the operating range. Initial humidification tests confirm the high sensitivity of the microsystem against small added masses, corresponding to an estimated detection limit on the order of 10⁻¹⁶ kg for the unfunctionalized device. In this way, the present work confirms the validity of the proposed triple-microcantilever configuration for ultra-low mass sensing and outlines its potential for future application in pathogen detection upon surface functionalization. Full article

This paper discusses a new method and sensor for the detection of ultra-low masses, such as those of viruses and biomarkers. The sensor contains three microcantilevers with a common substrate that vibrates. The detection method processes phase-shifted signals from Wheatstone bridges from connected piezoresistors formed on the vibrating microcantilevers and passive resistors on the rigid substrate. Each microcantilever has a gold pad that can be either active or passive. When a mass is detected, the shape of the amplitude–frequency response changes. The proposed method has high mass sensitivity and can respond up to one minute, which is an important challenge for nanocantilever sensors. Full article