NSF-BSF: CCSS: Resistance Tomography with 2D Sensor Membranes

今天的电脑和手机中的触控板和触摸屏有两个缺点——首先，它们是刚性的，其次，它们需要一个复杂的制造过程，需要许多单独的传感器。一种灵活且易于制造的压力传感器可以作为人和物体的人造皮肤，并可能为可穿戴计算机界面、触摸空间和生物医学运动诊断提供廉价便捷的解决方案。这种具有无线接口的设备将允许在传感器接口中易于使用。在一种称为电阻层析成像的非常规传感器测绘方法的帮助下，仅使用一块易于制造的压敏材料就可以创建这样一个平台来绘制压力。与标准传感器阵列相比，这种柔性传感器的设备制造微不足道，其复杂性转移到解释压力模式所需的信号处理上。使用各种触点组合的多次测量可以创建完整的压力图。预计从这项努力中开发出来的技术将导致用于可穿戴触摸板界面和生物医学运动诊断的新型柔性传感器。当今大多数二维（2D）触摸传感器和应变传感器需要单个传感器的索引阵列来收集空间信息，这在制造阶段需要显着的复杂性，同时损害了耐用性和更广泛的适用性。本研究提出了一种结合触摸传感和应变映射收集二维空间数据的新方法，该方法使用一种简单的制造复合膜作为空间压力传感器，通过层析映射算法将复杂性从制造转移到计算领域。本研究将基于泽尼克矩分析开发新的层析算法，将应变敏感膜外围的四点电阻测量转换为整个膜区域局部压力的二维图。该膜将由纳米管-硅酮导电复合橡胶制成。高效节能的测量架构和膜的无线接口将使这种应变传感器地图易于在各种机械，医疗，工程和个人用户应用中使用。低制造成本将使其成为无处不在的触摸传感器和可穿戴和万物互联应用的新型交互模式。传感器组件的简单制造方法和传感器在任何形状周围的一致性使得可批量生产，易于实现和高度通用的应变传感器和柔性触摸板。这里要研究的精确算法可以应用于更广泛的系统，扩展层析成像方法在传感中的效用。将开发导电弹性体传感器材料，以优化这里设想的层析成像应用。在此提案过程中产生的想法有望在传感器领域产生新的知识产权，例如用于计算机界面的柔性可穿戴触摸板，可能会产生新的工业产品。这种传感器的适形能力将在健康康复行业中得到更广泛的应用，例如用于健康监测的体层扫描袜子，可以感知肘部、膝盖或躯干的弯曲和机械张力。利用本文提出的技术，可以以极低的成本生产出耐用、持久、零维护的假肢和机器人触觉皮肤。这项工作将培养研究生批判性思维和设计方法的基本技能，以及应用数学、物理和材料设计方面的技能，其中包括本研究开发的新课程。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Touchpads and touchscreens in today's computers and cell phones have two disadvantages - first, they are rigid, and second, they require a complex manufacturing process with many individual sensors. A flexible and easy-to-manufacture pressure sensor could function as an artificial skin for people and objects and could lead to cheap and convenient solutions for wearable computer interfaces, touch enabled spaces, and biomedical movement diagnostics. Such a device with a wireless interface will allow for ease-of-use in sensor interfaces. With the help of an unconventional sensor mapping method called resistive tomography, it is possible to create such a platform using only a single piece of easy-to-manufacture pressure-sensitive material to map pressures. Device fabrication for such a flexible sensor is trivial in comparison to standard sensor arrays, with the complexity shifted to the signal processing needed to interpret the pressure pattern. Multiple measurements using various combinations of contacts can create the full pressure map. It is expected that the technology that is developed from this effort will lead to new kinds of flexible sensors for wearable touch-pad like interfaces and biomedical movement diagnostics.Most of today's two dimensional (2D) touch sensors and strain sensors require an indexed array of individual sensors in order to gather spatial information, requiring significant complexity in the fabrication stage, while impairing durability and broader applicability. This work proposes a new means of gathering 2D spatial data combining touch sensing and strain mapping that uses a trivial fabricated composite membrane to serve as the spatial pressure sensor, with the complexity shifted from fabrication to the computational domain through a tomographic mapping algorithm. This research will develop new tomographic algorithms based on a Zernike moment analysis to convert resistive four-point measurements at the periphery of a strain-sensitive membrane into a 2D map of the local pressures applied throughout the area of the membrane. The membrane will be made of a nanotube-silicone conducting composite rubber developed for this purpose. An energy-efficient measurement architecture and wireless interface to the membrane will allow this strain-sensor map to be easily employed in-the-field for various mechanical, medical, engineering, and personal-user applications. The low cost of fabrication will lend itself to ubiquitous touch sensors and novel modes of interaction for wearable and Internet-of-Everything applications. The trivial fabrication method of the sensor component and the conformability of the sensor around any shape make for a mass-producible, easily implemented, and highly versatile strain sensor and flexible touchpad. The exact algorithms to be investigated here can be applied on a much broader class of systems, expanding the utility of tomographic methods in sensing. The conducting elastomer sensor material will be developed to optimize the tomography application envisioned here. The ideas generated in the course of this proposal are expected to generate new intellectual property in the area of sensors, such as flexible, wearable touchpads for computer interfaces, likely to spawn new industry products. The conformal ability to shape such a sensor will lead to broader applications in the health industry for rehabilitation, such as a tomographic sock to sense bending and mechanical strain at the elbow, knee, or torso for health monitoring. Durable, long-lasting, zero-maintenance haptic skin for prosthetic limbs and robotics can be produced at extremely low cost with the technology proposed here. This effort will train graduate students in essential skills for critical thinking and design methodologies, as well as developing skills in applied math, physics, and materials design with newly developed courses including subject matter developed under this research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.