ProgrammableGrass: A Shape-Changing Artificial Grass Display Adapted for Dynamic and Interactive Display Features

TL;DR

ProgrammableGrass introduces a scalable, shape-changing grass display capable of LCD-like 8-bit color control by vertically actuating grass lengths at each pixel. A novel CIEDE2000-based grass color calibration system paired with a tablet-based workflow enables linear color mapping from grass length to 8-bit levels across multiple pixels, achieving up to $10$ fps animation on an $8\times8$ grid. Extensive indoor evaluations demonstrate high linearity (R$^2$>0.9) and reduced pixel-to-pixel variation when calibrating multiple grass pixels, with demonstrations including wave, path, text, and gesture-driven animations as well as practical applications. The work advances green-space-friendly interactive displays, enabling dynamic visuals on grass surfaces while addressing resolution scalability and color accuracy in reflective grass-based displays.

Abstract

There are various proposals for employing grass materials as a green landscape-friendly display. However, it is difficult for current techniques to display smooth animations using 8-bit images and to adjust display resolution, similar to conventional displays. We present ProgrammableGrass, an artificial grass display with scalable resolution, capable of swiftly controlling grass color at 8-bit levels. This grass display can control grass colors linearly at the 8-bit level, similar to an LCD display, and can also display not only 8-bit-based images but also videos. This display enables pixel-by-pixel color transitions from yellow to green using fixed-length yellow and adjustable-length green grass. We designed a grass module that can be connected to other modules. Utilizing a proportional derivative control, the grass colors are manipulated to display animations at approximately 10 [fps]. Since the relationship between grass lengths and colors is nonlinear, we developed a calibration system for ProgrammableGrass. We revealed that this calibration system allows ProgrammableGrass to linearly control grass colors at 8-bit levels through experiments under multiple conditions. Lastly, we demonstrate ProgrammableGrass to show smooth animations with 8-bit grayscale images. Moreover, we show several application examples to illustrate the potential of ProgrammableGrass. With the advancement of this technology, users will be able to treat grass as a green-based interactive display device.

Figures (24)

• Figure 1: Overview of (a, b) methods and (i, ii, iii) applications in ProgrammableGrass
• Figure 2: Position of our method relative to previous grass studies
• Figure 3: (a) Principle of spatial additive mixing in grass color and (b) Pixel structure using grass pin and grass multi-slit component
• Figure 4: Hardware concept design of grass module created by 3D modeling software
• Figure 5: Hardware system overview of grass module