Turn a Wall into a Touch Screen Cheap
图片来源：Brown Bird Design, “Wall : Room-Scale Interactive and Context-Aware Sensing,” by Yang Zhang et al. Presented at Chi Conference on Human Factors in Computing Systems, Montreal, April 21-26
研究人员用价值几百美元的材料，就把一堵墙变成了一个巨大的触摸屏。
[听力原文]（点击展开/收起）
Hi, I’m Scientific American podcast editor Steve Mirsky. And here’s a short piece from the July issue of the magazine, in the section called Advances: Dispatches from the Frontiers of Science, Technology and Medicine.Smart Walls by Prachi Patel
The right paint can add pizazz to your walls—and now it can also make them smarter. Researchers recently converted a wall into an outsize trackpad and motion sensor by using low-cost conductive paint to create a large grid of electrodes.
Such a smart wall can sense human touch and track gestures from a short distance. It can also detect the locations of appliances and whether they are switched on. The technology could someday turn on lights when a person enters a room, track a player"s motion in an interactive video game or monitor a child"s television use. “Walls are everywhere, so why not turn them into sensors for smart homes?” says Yang Zhang, a computer science doctoral student at Carnegie Mellon University, who helped to develop the concept.
To create the high-tech surface, Zhang and his colleagues applied painter"s tape in a lattice pattern to a 12-by-eight-foot wall, then coated it with commercially available conductive nickel paint. Removing the tape left a pattern of diamond-shaped electrodes, which the researchers connected using a grid of thin copper tape strips. They affixed a vinyl sticker in the middle of each diamond to insulate the electrodes from one another. Finally, they wired the strips to a custom-built circuit board and covered the wall with standard latex paint. The entire project took four hours and cost less than $200. Zhang and his colleagues at Disney Research presented the wall at the CHI Conference on Human Factors in Computing Systems in Montreal.
In tracking a touch or gesture, the wall functions similarly to a smartphone screen. The circuit board prompts the electrodes to emit an electric field; when a person"s body intercepts this field, it triggers a measurable change in current at the nearby electrodes.
In the wall"s appliance-detection mode, the power is turned off, and the electrodes act as an antenna to passively pick up electromagnetic waves emitted by nearby devices. The researchers detected iPads up to 6.5 feet away from the wall; fans and floor lamps could be sensed from about 10 feet.
[重难点词汇、短语]（点击展开/收起）
pizazz: n. 活力，气派
trackpad: n. 触控盘
conductive: adj. 有传导性的
grid: n. 网格
electrode: n. 电极
lattice: n. 格子框架
nickel: n. 镍
affix: v. 粘上
vinyl: n. 乙烯基塑料
insulate: v. 使…绝缘
circuit board: 电路板
prompt: v. 促使，导致，激起
emit: v. 发出，射出
intercept: v. 拦截，拦阻
antenna: n. 天线
[参考译文]（点击展开/收起）
嗨，我是科学美国人播客节目编辑Steve Mirsky。以下是杂志7月发行的一篇短文，来自栏目“进展：科学、技术和医学前沿速报”。让我们来听听普拉奇·帕特尔（Prachi Patel）描写的智能墙壁吧。
合适的涂料可以为你的墙壁增添活力，而现在，它也能让你的墙壁更加智能。研究人员用低成本的导电涂料制作了一张巨大的电极网格，将墙面变成了一个超大的触摸屏兼运动传感器。
这种智能墙壁可以感知人的触摸，并在短距离内跟踪手势，还可以检测设备的位置及运行状态；有朝一日，这项技术甚至可以在有人进入房间时打开灯、在交互式电子游戏中跟踪玩家的动作，或者监控孩子的电视使用情况。“墙壁无处不在，为什么不把它们变成智能家居的传感器呢？” 帮助开发“智能墙壁”这一概念的张扬（音译，Yang Zhang）说，他是卡内基梅隆大学（Carnegie Mellon University）的计算机科学博士生。
为了创造出高科技墙面，张的团队在一堵12×8平方英尺（约3.6×2.4平方米）的墙上，将画家用的胶带贴成格子图案，然后涂上市售的导电镍漆。撕去胶带后，墙面上会留下菱形的电极图案，接下来研究人员用薄铜带网格将其连接起来。他们在每个菱形的中心贴上乙烯基贴纸，使电极彼此绝缘。最后，他们把这些金属条连接到一块定制的电路板上，然后用普通的乳胶漆覆盖墙壁。整个项目花了四个小时，费用不到200美元。在蒙特利尔的计算机系统人为因素会议（ CHI Conference on Human Factors in Computing Systems）上，张和迪士尼研究中心（Disney Research）的同事展示了这面墙。
在跟踪触摸或手势时，墙壁的功能类似于智能手机屏幕：电路板促使电极发射电场；当人的身体截断了这个磁场时，就会触发附近电极电流的可测量变化。
在墙壁的设备检测模式（appliance-detection mode）中，电源会关闭，电极将充当天线被动接收附近设备发出的电磁波。研究人员可以检测到最远离墙6.5英尺（约2米）处的平板电脑，和10英尺（约3米）处的风扇及落地灯。
翻译 路畅
