ITR/PE+SY Digital Clay for Shape Input and Display

形状是成功沟通、解释和理解工程、艺术、科学和医学几乎所有领域复杂数据的关键因素。 虽然近年来，基于平面图像的可视化极大地增强了表单和复杂数据的通信，但计算能力已经达到可以考虑实时交互式3D物理通信的程度。 在这个项目中，PI将开发一种新的交互式2D或3D触觉计算机接口，使用户指定的形状显示从计算机输出，并用户直接输入的形状到计算机。 这种所谓的“数字粘土”将允许用户传达和/或感知多元素、平行的信息链。 它是一种分布式输入/显示设备，其表面可以由用户成形并由计算机获取;或者，粘土可以由计算机成形以供用户检查。 像普通的粘土一样，数字粘土将允许一个中等大小的区域被触摸，用压力重塑，并以真正的3D形式被用户看到。 与普通粘土不同，数字粘土还向计算机提供参数，这些参数将代表计算机的形状，以进行进一步分析，存储，复制，通信和/或修改;或者，允许计算机指定其形状。 粘土的这种组合输入和输出功能使计算机和用户之间的双向通信成为可能。 类似数字粘土的设备的一些先前的实现方式集中于使用到存储虚拟粘土的计算机的类似手套或触觉操纵器接口来重塑“虚拟粘土”的非物理体积。 PI的方法是不同的;数字粘土包括一个仪器化的，驱动的，计算机接口的物理体积，由一个可驱动的表面作为触觉接口。 该表面由可控互连流体驱动致动器的行或阵列移位，这些致动器一起作用以通过操纵粘土体积内部的立体光刻支架来传送3D物体的表面形貌。 每个致动器包括离散的流体可膨胀单元，该流体可膨胀单元通过与压力传感器集成的专用双向微型阀连接到两个公共加压贮存器（在基座内），该压力传感器由格鲁吉亚技术学院现有的MEMS技术制造。 每个离散表面元素的位置可以由用户或主机改变。 体积流量的简单测量与适当的基于软件的运动学分析相结合，可以确定粘土的整个体积，从而确定其表面的坐标。 数字粘土的独特特征在于，致动离散化表面所需的力完全来自两个流体储存器，从而消除了对可能具有有限扭矩或线性力的小规模电驱动致动器的需要。 这种流体方法克服了由致动器能量密度限制以及分布式布线和感测要求所施加的约束，这些约束迄今为止阻止了诸如数字粘土的结构成为现实。 此外，用户可以通过感测和克服由液体压力施加的力来与主计算机交互地激活装置，以伴随地将装置的形状设置（或重置）为期望的状态。 在这个项目中，PI将开发和演示数字粘土硬件，其计算机接口和相关软件，并将进一步说明其在感兴趣的应用中的功效（例如，计算机辅助设计、医学和生物工程诊断以及可重新配置的输入/输出显示器）。 特别值得注意的是数字粘土的潜力，以帮助视障人士接收/发送触觉信息从/到计算机。

Shape is a key element in successful communication, interpretation, and understanding of complex data in virtually every area of engineering, art, science, and medicine. While in recent years the communication of both form and complex data have been greatly enhanced by visualization that is based on planar images, computational power has reached the point where it is possible to consider real-time interactive 3D physical communication. In this project, the PI will develop a novel interactive 2D or 3D haptic computer interface that enables both user-specified display of shapes as output from a computer, and user-directed input of shapes to a computer. This so-called "digital clay" will allow users to convey and/or sense multiple-element, parallel information strands. It is a distributed input/display device, the surface of which can be shaped by a user and acquired by a computer; alternatively, the clay can be shaped by the computer for the user to examine. Like ordinary clay, digital clay will allow an area of moderate size to be touched, reshaped with pressure, and seen by the user in true 3D form. Unlike ordinary clay, digital clay also provides parameters to the computer that will represent the shape to the computer for further analysis, storage, replication, communication and/or modification; or, will allow the computer to prescribe its shape. This combined input and output feature of the clay enables two-way communication between the computer and the user. Some previous implementations of digital-clay-like devices have focused on reshaping of non-physical volumes of 'virtual clay' using glove-like or haptic manipulator interfaces to a computer in which the virtual clay is stored. The PI's approach is different; digital clay comprises an instrumented, actuated, computer-interfaced physical volume bounded by an actuatable surface that acts as the haptic interface. This surface is displaced by rows or arrays of controllable interconnected fluidic-driven actuators, which together act to convey the surface topography of 3D objects by means of manipulation of a stereolithographed scaffold internal to the volume of the clay. Each actuator comprises a discrete fluidically-inflatable cell that is connected to two common pressurized reservoirs (within a base) through a dedicated two-way miniature valve integrated with a pressure sensor, manufactured by MEMS technology existing at Georgia Tech. The position of each discrete surface element can be altered either by the user or by the host computer. The simple measurement of volume flow rate combined with suitable software-based kinematic analysis allows the determination of the entire volume of the clay, and therefore the coordinates of its surface. A unique feature of the digital clay is that the force that is necessary to actuate the discretized surface is derived entirely from the two fluidic reservoirs, thus eliminating the need for small-scale, electrically-driven actuators that may have limited torque or linear force. This fluidic approach overcomes the constraints imposed by actuator energy density limits, and distributed wiring and sensing requirements, that have heretofore prevented structures such as digital clay from becoming a reality. Furthermore, the user can activate the device interactively with the host computer by sensing and overcoming the force that is exerted by the liquid pressure to concomitantly set (or reset) the shape of the device to a desired state. In this project the PI will develop and demonstrate the digital clay hardware, its computer interface, and associated software, and will further illustrate its efficacy in applications of interest (e.g., computer-aided design, medical and bioengineering diagnostics, and reconfigurable input/output displays). Of particular note is the potential of digital clay to aid visually impaired persons in receiving/sending haptic information from/to a computer.