Shape display devices composed of actuation pixels enable dynamic rendering of surface morphological features, which have important roles in virtual reality and metaverse applications. The traditional pin-array solution produces sidestep-like structures between neighboring pins and normally relies on high-density pins to obtain curved surfaces. It remains a challenge to achieve continuous curved surfaces using a small number of actuated units. To address the challenge, we resort to the concept of surface continuity in computational geometry and develop a C0-continuity shape display device with trichamber fiber-reinforced soft actuators. Each trichamber unit produces three-dimensional (3D) deformation consisting of elongation, pitch, and yaw rotation, thus ensuring rendered surface continuity using low-resolution actuation units. Inspired by human tactile discrimination threshold on height and angle gradients between adjacent units, we proposed the mathematical criteria of C0-continuity shape display and compared the maximal number of distinguishable shapes using the proposed device in comparison with typical pin-array. We then established a shape control model considering the nonlinearity of soft materials to characterize and control the soft device to display C0-continuity shapes. Experimental results showed that the proposed device with nine trichamber units could render typical sets of distinguishable C0-continuity shape sequence changes. We envision that the concept of C0-continuity shape display with 3D deformation capability could improve the fidelity of the rendered shapes in many metaverse scenarios such as touching human organs in medical palpation simulations.

中文翻译：

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受感知启发的 C0 连续性触觉形状显示器，带有三腔软致动器。


由驱动像素组成的形状显示设备能够动态渲染表面形态特征，这在虚拟现实和元宇宙应用中具有重要作用。传统的 pin-array 解决方案在相邻 pins 之间产生类似 sidestep 的结构，通常依靠高密度 pins 来获得曲面。使用少量驱动单元实现连续的曲面仍然是一个挑战。为了应对这一挑战，我们采用了计算几何中的表面连续性概念，并开发了一种带有三室纤维增强软致动器的 C0 连续性形状显示设备。每个三室单元都会产生三维 （3D） 变形，包括伸长、俯仰和偏航旋转，从而使用低分辨率驱动单元确保渲染表面的连续性。受人类触觉辨别阈值对相邻单元之间高度和角度梯度的启发，我们提出了 C0 连续性形状显示的数学标准，并将使用所提出的设备与典型引脚阵列相比可区分形状的最大数量进行了比较。然后，我们建立了一个考虑软材料非线性的形状控制模型，以表征和控制软器件显示 C0 连续性形状。实验结果表明，所提出的具有 9 个三室单元的装置可以呈现典型的可区分的 C0 连续性形状序列变化集。我们设想，具有 3D 变形功能的 C0 连续性形状显示的概念可以提高许多元宇宙场景中渲染形状的保真度，例如在医疗触诊模拟中触摸人体器官。