①Ultrasonic Embossment of Acrylic Sheets with Transparency Control (ACM SIGGRAPH 2023 Labs)

This paper discusses a new processing technology for acrylic sheets using high-intensity focused ultrasound (HIFU). Acrylic are widely used due to their transparency and weather resistance, but current processing methods cannot create embossing features without reductive manufacturing methods. HIFU emits ultrasonic waves that melt the surface of the acrylic sheet, creating bumps that can be controlled by adjusting the irradiation time, speed, distance, and amplitude. This technology can control transparency, line thickness, and tactility and can create bumps and depressions instantaneously, making it potentially useful for embossing, etching, and braille generation. The paper demonstrates the controllable variables of the HIFU approach and highlights its potential for industry as a high-precision acrylic plate processing technology.

Authors: Ayaka Tsutsui / Tatsuki Fushimi / Kengo Tanaka / Takahito Murakami / Yoichi Ochiai

②HIFU Embossment of Acrylic Sheets (ACM CHI 2024)

Tactile interfaces such as embossment facilitate information transfer through touch in Human-Computer Interaction (HCI). Traditional embossing methods, while enabling the creation of intricate patterns, face limitations due to mold reliance and material thickness restrictions, hindering bespoke embossment creation. In this study, we propose High-Intensity Focused Ultrasound (HIFU) as an alternative technique to produce tailored embossed designs on acrylic without the need for traditional molds. We uncover specific HIFU parameters, such as amplitude, irradiation time, and distance that directly impact essential qualities of embossment including embossment height, transparency, and line generation. Additionally, the capability of embossing without the use of molds expands the applications for quick prototyping and customization of embossed designs within HCI. Furthermore, we introduce a user interface developed to streamline the design and application of customizable tactile graphics using HIFU, aimed at non-expert users. Preliminary user studies reveal positive feedback on the interface’s intuitiveness and the quality of the HIFU embossment. Our study indicates that HIFU embossment presents a viable approach for creating embossed features in interactive systems, with the potential to offer methods for personal customization in the design of tactile materials.

Authors: Ayaka Tsutsui / Tatsuki Fushimi / Takahito Murakami / Ryosei Kojima / Kengo Tanaka / Yoichi Ochiai

(This acrylic was held by Kuchibashi (made by Murakami))