Design and Validation of Single-Axis 3D-Printed Force Sensor Based on Three Nested Flexible Rings.

Force measurement serves as a fundamental requirement across diverse engineering disciplines, ranging from aerospace engineering to consumer electronics where precise load monitoring is essential for safety and performance. Prior research has shown that conventional sensing technologies frequently encounter obstacles related to high production costs or substantial inaccuracies in data acquisition that limit their utility in large-scale applications. These limitations often restrict the deployment of high-precision instruments in cost-sensitive industrial environments where budget constraints are paramount and traditional strain gauges prove too expensive for widespread use. Existing solutions typically rely on complex fabrication processes that hinder rapid prototyping and prevent the scalable manufacturing of custom sensor geometries required for specialized mechanical interfaces. It was already known that flexible structures can translate mechanical stress into measurable physical changes, yet the optimization of these shapes for modern additive manufacturing remained largely unexplored. This absence of evidence motivated the exploration of additive manufacturing techniques to create more accessible and reliable force-detecting hardware using nested geometries to improve sensitivity.

This research introduces a novel sensing device utilizing three nested flexible rings produced via 3D additive manufacturing to measure external loads with high precision and low cost. The investigators sought to overcome the financial and technical barriers associated with traditional force-sensing hardware by utilizing inexpensive thermoplastic materials and simplified assembly techniques. By leveraging displacement variations within the ring structure, the design aims to provide a precise correlation between applied force and physical deformation across a broad measurement range. The project focuses on establishing a robust mathematical framework to describe the nonlinear behavior of these nested components under varying mechanical stresses and environmental conditions. Researchers intended to validate the structural integrity and functional accuracy of the 3D-printed components through rigorous testing against established benchmarks to ensure industrial readiness. This gap motivated the creation of a low-cost alternative suitable for integration into robotics, the automotive industry, and iatrical equipment where affordability is a primary concern.

The fabrication process employed 3D additive manufacturing to construct the triple-ring architecture from flexible materials with specific elastic moduli that allow for repeatable deformation cycles. An analytical model based on the minimal energy method was formulated to characterize the force-displacement relationship within the nested system to predict performance accurately. This mathematical approach specifically addresses the inherent nonlinearity found in the deformation of nested circular geometries during compression and tension phases of operation. Finite Element Method (FEM) simulations provided a computational environment to predict the mechanical response of the sensor under various loading conditions before physical prototypes were produced. Physical experiments were conducted to compare real-world performance data against the theoretical and simulated predictions using calibrated weights and high-precision displacement sensors. The integration of these diverse evaluative techniques ensured a comprehensive assessment of the sensor's operational reliability and measurement sensitivity across its entire functional range.

Both FEM simulations and physical experiments confirmed the effectiveness of the nested ring design for accurate force detection across a wide range of inputs and environmental variables. The analytical model successfully elucidated the complex force-displacement correlation, accounting for the nonlinear properties of the flexible rings during structural loading and unloading phases. Observations indicated that the displacement variations within the three nested rings provided a sensitive metric for quantifying external forces with minimal error compared to traditional single-ring designs. The 3D-printed prototypes demonstrated consistent performance across multiple testing cycles, validating the durability of the additive manufacturing approach for long-term use in demanding industrial environments. Data analysis showed that the sensor maintains high precision while significantly reducing the expenses typically associated with force measurement in industrial settings and research laboratories. The results established a clear link between the geometric configuration of the rings and the resulting measurement accuracy observed during the experimental validation phase.

The development of this 3D-printed force sensor offers a cost-effective solution for high-precision engineering applications requiring reliable load monitoring without the burden of high capital expenditure. Its simplified manufacturing process suggests significant potential for rapid deployment in the automotive industry and advanced robotics where custom sensor shapes are frequently required. The findings indicate that nested flexible structures can effectively replace more expensive traditional sensing components without sacrificing performance or data integrity in real-world operating conditions. Future integration into iatrical equipment could enhance the sensitivity and affordability of medical diagnostic tools used in patient care and rehabilitation robotics. This research paves the way for further exploration of additive manufacturing in the production of complex mechanical sensors with tailored properties for specific industrial needs. The study concludes that the triple-ring geometry provides a reliable foundation for single-axis force measurement in diverse technical fields including automation and transport.