Robust hand motion tracking holds promise for improved human-machine interaction in diverse fields, including virtual reality, and automated sign language translation. However, current wearable hand motion tracking approaches are typically limited in detection performance, wearability, and durability. This article presents a hand motion tracking system using multiple soft polymer acoustic waveguides (SPAWs). The innovative use of SPAWs as strain sensors offers several advantages that address the limitations. SPAWs are easily manufactured by casting a soft polymer shaped as a soft acoustic waveguide and containing a commercially available small ceramic piezoelectric transducer. When used as strain sensors, SPAWs demonstrate high stretchability (up to 100%), high linearity (R2 > 0.996 in all quasi-static, dynamic, and durability tensile tests), negligible hysteresis (<0.7410% under strain of up to 100%), excellent repeatability, and outstanding durability (up to 100,000 cycles). SPAWs also show high accuracy for continuous finger angle estimation (average root-mean-square errors [RMSE] <2.00°) at various flexion-extension speeds. Finally, a hand-tracking system is designed based on a SPAW array. An example application is developed to demonstrate the performance of SPAWs in real-time hand motion tracking in a three-dimensional (3D) virtual environment. To our knowledge, the system detailed in this article is the first to use soft acoustic waveguides to capture human motion. This work is part of an ongoing effort to develop soft sensors using both time and frequency domains, with the goal of extracting decoupled signals from simple sensing structures. As such, it represents a novel and promising path toward soft, simple, and wearable multimodal sensors.

中文翻译：

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使用软聚合物声波导阵列的可穿戴实时手部运动跟踪系统的设计。

强大的手部动作跟踪有望改善虚拟现实和自动手语翻译等不同领域的人机交互。然而，当前的可穿戴手部运动跟踪方法通常在检测性能、可穿戴性和耐用性方面受到限制。本文介绍了一种使用多个软聚合物声波导 (SPAW) 的手部运动跟踪系统。SPW 作为应变传感器的创新用途提供了解决这些限制的多项优势。SPAW 可以通过铸造形状为软声波导的软聚合物轻松制造，并包含市售的小型陶瓷压电换能器。当用作应变传感器时，SPAW 表现出高拉伸性（高达 100%）、高线性度（在所有准静态、动态和耐久性拉伸测试中 R2 > 0.996）、可忽略不计的滞后（在高达 100% 的应变下 <0.7410%） ）、出色的重复性和出色的耐用性（高达 100,000 次循环）。SPAW 还显示出在各种屈曲-伸展速度下连续手指角度估计的高精度（平均均方根误差 [RMSE] <2.00°）。最后，设计了基于SPAW阵列的手部跟踪系统。开发了一个示例应用程序来演示 SPAW 在三维 (3D) 虚拟环境中实时手部运动跟踪的性能。据我们所知，本文详细介绍的系统是第一个使用软声波导来捕获人体运动的系统。这项工作是开发使用时域和频域的软传感器的持续努力的一部分，其目标是从简单的传感结构中提取解耦信号。因此，它代表了一条通往软、简单和可穿戴多模态传感器的新颖且有前途的道路。