This paper presents the design, optimization, fabrication and characterization of a symmetrical two-axis tilt angle sensor. The sensor consists of a globe-calotte-shaped excitation electrode and two pairs of sensing electrodes of the same dimensions, positioned symmetrically on a 3D printed hollow sphere. The sphere is filled with oil and air, and then mounted on the surface of a printed circuit board (PCB) for mechanical packaging and measurement. Experimental results show that the sensor can measure the tilt angle in both the x- and y-axes with sensitivity of 124 mV/° and resolution of ±0.15° in the range from −35° to 35°. The characteristics of the sensor on the x- and y-axes are similar. The proposed sensor can be used in several applications.

This paper presents the design, fabrication, and characterization of a two-axis tilt angle sensor based on the air/liquid two-phase dielectric capacitive sensing structure. The sensor consists of five electrodes, one serves as the exciting electrode and two pairs of electrodes as sensing ones, which are arranged at identical positions surrounding a glass cylinder tube. The glass cylinder tube is partly filled with dielectric liquid to form the air/liquid two-phase dielectric medium. Based on this arrangement, the proposed sensor can detect roll and pitch angles, simultaneously. A computational simulation and experimental measurements are performed to study the performance of the sensor. The numerical simulation is carried out with a finite element analysis using COMSOL. A prototype of the sensor was fabricated, and its performance was evaluated. The tilt angle sensor was employed on a printed circuit board with a conditioning circuit, consisting of a sine wave generator, pre-amplifiers, rectifiers, and low pass filters. The experiment results confirmed that the roll angle detection has a linear range in the range of −60° to +60° with non-linearity error of 6.6%. The sensitivity and resolution in this range are 18.2 mV/° and 0.55°, respectively. For pitch angle detection, the linear range is −16° to +16° with non-linearity of 10%, and sensitivity and resolution of 58.2 mV/° and 0.17°, respectively.

This paper presents a design optimization and validation of a two-axis cylindrical capacitive tilt angle sensor. The proposed sensor includes of five electrodes symmetrically arranged surrounding an air–liquid two phases cylindrical tube, forming two pairs of electrodes for roll and pith angle measurement. Cylindrical plastic tube filled partly with dielectric fluid with dielectric constant of 2. The proposed sensor can detect tilt angles in x-axis and y-axis, i.e. roll and pith angles. When the cylindrical plastic tube is rotated, the dielectric fluid covers a portion of the induction electrodes, thereby changing the differential capacitance value of the capacitor corresponding to the tilt angle. By measuring the capacitance change, the tilt angle can be estimated. Performance of the sensor was investigated by Finite element method using Comsol Multiphysics simulation software. Simulation results show the variation in capacitance with respect to the variation of tilt angle. Based on this simulation model, the structure of the electrodes was manipulated for maximizing the sensitivity for roll and pith sensing in an appropriate working range. Experiments were also conducted for validation. The experiment results are well matched with simulated results. The optimized sensor has working range from −70° to +70° with sensitivity of 3 mV/° in the roll angle and from −30° to +30° with sensitivity of 17 mV/° in the pitch angle.

3D printing technology has enabled the development of low-cost, highly customizable sensors by providing rapid fabrication and flexible design capabilities. This study introduces a rapid design and fabrication workflow for accelerometers, utilizing a one-step 3D printing process combined with an optical window-light method for displacement detection. The accelerometer is fabricated using Polyethylene Terephthalate Glycol (PETG) filament, with the proof mass and springs printed as part of the process. The optical window-light intensity measurement method is employed to detect micrometer-scale displacements, facilitating the detection of variable acceleration. This approach offers significant benefits, including simple design, elimination of additional metallization or assembly steps, and avoidance of complex integrated measurement circuitry. The proposed 3D-printed accelerometer demonstrates a resolution of 10 mg and operates over a wide measurement range of -2 to 2 g with linearity and strong dynamic response. This workflow provides an efficient solution for customized MEMS device production and showcases the potential of the optical window-light method for low-cost accelerometer development.

This research presents a rigorous investigation into the structural optimisation and material-driven performance enhancement of 3D-printed inertial transducers, specifically focusing on the transition from monolithic thermoplastics to carbon fibre-reinforced composites (PETG-CF). Conventional Polyethylene Terephthalate Glycol (PETG) has been demonstrated functional viability under ambient conditions; however, its susceptibility to temperature-induced mechanical fluctuations and viscoelastic degradation remains a barrier to precision applications. The present study employs integrated modal, harmonic, and thermo-mechanical Finite Element Method (FEM) analysis to delineate the relationship between matrix reinforcement and operational stability across an extended thermal gradient from -40 °C to 100 °C. The analytical model yielded resonant frequencies at ambient temperature of 62.38 Hz for PETG and 102.62 Hz for PETG-CF, demonstrating a high correlation with FEM simulation results of 62.94 Hz and 103.71 Hz, respectively. The simulation results indicate that standard PETG-based transducers exhibit high thermal sensitivity, with the fundamental natural frequency decreasing from 67.1 Hz at −40 °C to 47.0 Hz at 75 °C, representing a linear frequency drift of approximately 0.32 Hz/°C. Conversely, the incorporation of carbon reinforcement (PETG-CF) significantly enhances mechanical resonance performance, achieving a fundamental natural frequency of 103.71 Hz at 25 °C, corresponding to a 65% increase over the baseline (62.945 Hz). The PETG-CF variant demonstrates superior thermal robustness, evidenced by a reduced average frequency shift of approximately 0.26 Hz/°C. The experimental validation of these findings was conducted through the utilisation of free-decay vibration measurements, which substantiated the observations. The resonant frequencies observed were found to be approximately 71 Hz for PETG and 106 Hz for PETG-CF. Static calibration yielded a sensitivity of approximately 108 mV/g. The results obtained establish a practical operational temperature limit between -40 °C and 75 °C, thus providing a fundamental framework for developing high-performance, low-cost micro-sensors through advanced Fused Deposition Modeling (FDM) techniques.