# Interactive "Electronic Ink" Walls for Science Museums and Exhibition Halls: How They Work > An "electronic ink" interactive wall is a wall printed with line drawings that comes alive when touched: a projector adds moving ink, animation and information panels, and a 2D LiDAR ("radar") scanner detects hands on the wall. The name describes the effect, not E Ink paper. MLABART built one at the Shanghai Urban Planning Exhibition Center. **Published:** 2026-10-17 - **By:** MLABART ## What is an "electronic ink" interactive wall? "Electronic ink interactive wall" (电子墨水互动墙) is a name used in Chinese exhibition projects. In the version MLABART builds, it is a wall that looks like a printed illustration until someone touches it. The line drawings are printed or painted on the wall itself. A projector aligned to those drawings adds the moving part -- ink spreading through a drawing, an animation, or an information panel opening next to it -- and a sensor tells the software where the wall was touched. The name describes the effect, not the hardware. It is not built from E Ink electronic-paper displays: the ink is projected light. Suppliers sometimes use the same name for walls built differently, so a brief should ask how the wall is actually made. ## How does it work? The wall MLABART built uses projection plus radar touch -- in China's installation industry "radar" here means a 2D laser scanner (LiDAR). The chain has four steps: - Touch: a 2D LiDAR at a top corner sweeps a thin plane of infrared light a few centimetres in front of the wall and reports where a hand breaks it. - Map: the sensor's coordinates are calibrated to the projected image, so a touch lands on the drawing the visitor meant. - Respond: the content software decides what that drawing does -- spread ink, play an animation or open an information panel. - Project: the projector draws the response onto the printed drawing, so the illustration appears to come alive. - [Related: Interactive radar for touch walls and floors -- ranges, installation and common faults](https://mlabart.com/insights/interactive-radar-lidar-installation-guide/) - ![General-principle diagram of an electronic-ink interactive wall. Side view: line drawings printed on the wall, a projector in front adding projected ink and panels, and a 2D LiDAR at the top corner sweeping a scan plane a few centimetres in front of the wall, which a hand breaks. Signal chain: touch, map sensor coordinates to the projected image, respond in the content software, project the response onto the drawing that was touched.](https://mlabart.com/insights/e-ink-interactive-wall-science-museum/how-it-works.svg) ## MLABART at the Shanghai Urban Planning Exhibition Center MLABART built an electronic-ink interactive wall for the Shanghai Urban Planning Exhibition Center in 2022, using projection and radar touch. MLABART's scope covered the interactive software, the content, installation, and debugging and commissioning of the interactive software on site. On the wall, line drawings of city life and a row of round touch points are printed on a light grey surface. Touching a point opens a projected information panel beside the drawing; further along, a long streetscape drawing carries projected screens and panels that light up in the same way. Because the drawings are printed and the moving content is projected, the exhibit can change what it says without repainting the wall. - [Shanghai Urban Planning Exhibition Center -- Wikipedia](https://en.wikipedia.org/wiki/Shanghai_Urban_Planning_Exhibition_Center) - ![Visitors at the electronic-ink interactive wall in the Shanghai Urban Planning Exhibition Center: one reaches out to a round touch point on a light grey wall printed with line drawings, and a projected information panel appears beside the drawing.](https://mlabart.com/insights/e-ink-interactive-wall-science-museum/planning-hall-touch.jpg) - ![A long streetscape line drawing printed on the wall of the Shanghai Urban Planning Exhibition Center, with projected screens and information panels glowing inside the drawing and a display ledge below.](https://mlabart.com/insights/e-ink-interactive-wall-science-museum/planning-hall-streetscape.jpg) ## Why science museums and exhibition halls use it Exhibition halls have a lot to explain and visitors who will not read long panels. An electronic-ink wall breaks one large subject into many small drawings, each of which answers a question when touched, so a family can explore at its own pace and several people can use different parts of the wall at once. The format also suits the way public venues operate. The surface is a printed wall with no screen to crack; the sensor never needs to be touched; and the content lives in software, so a hall can update facts or add a new story without changing the build. These are general advantages of projection over printed artwork, and they depend on the planning points below. ## How it compares with walls that look similar Three kinds of interactive wall often appear in the same exhibition brief. They are built differently and suit different jobs: - [Related: Interactive digital graffiti walls -- how they work](https://mlabart.com/insights/interactive-graffiti-wall-guide/) - ![General-principle comparison of three interactive walls. Electronic-ink wall: projection over printed drawings with radar touch; the visitor touches a drawing and ink or an information panel appears; best for explaining many small topics on one wall with long daily hours. Interactive graffiti wall: tracked spray can, stylus or hands on an LED or projected canvas; the visitor paints and the finished piece is captured; best for creative play and a souvenir. Touchscreen or LED touch wall: a display with built-in touch used like a large tablet; best for dense information, menus and video.](https://mlabart.com/insights/e-ink-interactive-wall-science-museum/three-walls-compared.svg) ## What to plan before you build one Most of the work is decided before installation day. These points apply to any projection-and-radar wall: - Artwork and projection together: the printed line drawings and the projected content are designed as one layer, and the projector is aligned to the print, not the other way round. - Light: projection needs controlled ambient light on the wall; daylight or spotlights on the surface wash out the ink. - Shadows: place the projector so a visitor standing at the wall does not block their own content -- short-throw or high mounting helps. - Touch height: put touch points where the audience can reach, including children if they are the main visitors. - Several visitors at once: one LiDAR can be blocked by one person's arm; wide or busy walls usually need a second sensor. - Daily operation: projector lifespan and cleaning, automatic start-up at opening time, and a way to update content without opening the wall. ## Sources The Shanghai Urban Planning Exhibition Center wall is described from MLABART's own project record and video. The working principle and planning points are general practice for projection and 2D LiDAR touch walls, not a specification of a particular build. - [MLABART -- interactive radar (2D LiDAR) guide with manufacturer specifications](https://mlabart.com/insights/interactive-radar-lidar-installation-guide/) - [Shanghai Urban Planning Exhibition Center -- Wikipedia](https://en.wikipedia.org/wiki/Shanghai_Urban_Planning_Exhibition_Center) ## FAQ ### Is an electronic-ink interactive wall made of E Ink displays? Not in the version MLABART builds. The line drawings are printed on the wall, a projector adds the moving ink and information, and a 2D LiDAR (radar) detects touch. The name describes the effect; ask a supplier how their wall is actually built. ### How does the wall know where it was touched? A 2D LiDAR at a top corner sweeps a thin infrared plane a few centimetres in front of the wall and reports where a hand breaks it. Software calibrates those coordinates to the projected image, so the touch lands on the right drawing. ### Can the content be changed after installation? Yes. The moving content is projected from software, so text, animations and stories can be updated without repainting the wall, as long as they still match the printed drawings -- or the print is updated too. ### Has MLABART built an electronic-ink interactive wall? Yes. MLABART built one for the Shanghai Urban Planning Exhibition Center in 2022 using projection and radar touch, covering the interactive software, content, installation and on-site debugging of the interactive software. ## Related Pages **See also:** [Digital Exhibition Halls & Showrooms](https://mlabart.com/solutions/digital-exhibition-halls/) | [Projection Mapping](https://mlabart.com/solutions/projection-mapping/) | [Motion & Body-Tracking Interactives](https://mlabart.com/solutions/motion-tracking-interactives/) | [Interactive Digital Graffiti Wall](https://mlabart.com/solutions/interactive-graffiti-wall/) --- **MLABART** -- Interaction - Imagination - Innovation MLABART is an interactive installation and interactive software development studio. We design, program and deliver interactive installations -- motion-sensing games, touch and AI experiences, interactive LED walls, projection mapping, naked-eye 3D and kinetic sculptures -- for mall and New Year's Eve countdown campaigns, trade-show booths and launches, and brand pop-ups, from concept and custom software through fabrication and on-site delivery. - Web: https://mlabart.com - Email: mark@touchworld-sh.com - Phone / WhatsApp: +86 18917292695 - Canonical HTML version: https://mlabart.com/insights/e-ink-interactive-wall-science-museum/