Paper Reading #1 (as in the one I have to present):  ZeroN:  Mid-Air Tangible Interaction Enabled by Computer Controlled Magnetic Levitation

Intro

The paper that I consented to be assigned is called "ZeroN:  Mid-Air Tangible Interaction Enabled by Computer Controlled Magnetic Levitation".  But you probably knew that from the blog heading.  It was written by researches in the MIT Media Laboratory and MIT Center for Bits and Atoms.  The researchers are as follows:

Jinha Lee, MIT Media Laboratory is a Ph.D student and research assistant at Tangible Media Group.  His other works are a See-through 3D desktop, and "Beyond" - a collapsible input device.

Rehmi Post, MIT  Center for Bits and Atoms, is a visiting scientist in the Physics and Media group, directed by Neil Gershenfeld.  Some of his other work includes multi-touch displays and wearable interfaces.

Hiroshi Ishii, MIT Media Laboratory, is Associate Director at the Media Lab, and founded the Tangible Media Group.  His other work includes TeamWorkStation and ClearBoard.

Summary

A tangible interface attempts to render virtual objects in the physical world.  The problem with existing tangible interfaces is that they are often restricted to two dimensional space, due to gravity, or that their lateral range of motion is quite limited.  The goal of the ZeroN project was to create a new 3D tangible interface that represent objects in seemingly anti-gravitational motion.

This was achieved by using a single powerful solenoid electromagnet that was suspended several inches above the table.  ZeroN is the name of the magnetic ball that this solenoid levitates beneath it.  The solenoid holds ZeroN in place by pulsing rapid magnetic fields, which continually pull ZeroN up when active, and let it fall when inactive.  The whole system is moved laterally by an x and z axis motor based on user input to maintain that the solenoid remains over ZeroN.  The location of ZeroN is tracked by two PlayStation Eyecams.  To ensure that ZeroN doesn't drift off on its own, the user's hands are detected by an Xbox kinect sensor.

There is added functionality for the system that allows images to be projected onto ZeroN, such as a planet's surface or a camera.  There is also playback capability, where the user must hold ZeroN for 2.5 seconds, and then move it along the path they want ZeroN to follow.  Upon release, ZeroN will retreat to its original position, and then follow the path that the user created.

ZeroN introduces a novel interaction language: (a) Users places ZeroN in the air; (b) the computer actuates ZeroN and users intervene with the movement of ZeroN; (c) digital item attached to ZeroN; (d) ZeroN translated and rotated in the air; (e) long hold used to record and play back.

Related Work (not referenced in the paper)

The concept of tangible user interfaces must not be thoroughly explored, because nearly all of the papers listed below reference at least one paper that has also been referenced in the article I am writing about.

These four projects had a practical application, and that was usually to help industries engineer their product, or the process to create a product:

Augmented Urban Planning Workbench:  http://web.mit.edu/ebj/www/ISMAR02paperFinal.pdf

InfrActables:  http://dl.acm.org/citation.cfm?id=1130237.1130444
Tangible Factory Planning: http://www.danielguse.de/tangibletable.php
Tangible User Interface For Supporting Disaster Education:  http://dl.acm.org/citation.cfm?id=1280877

These other projects had a much more novel focus, be it drawing, or music production.  Actually, a good number of tangible user interfaces were aimed at dynamic music production.
MightyTrace:  http://dl.acm.org/citation.cfm?id=1357091&dl=ACM&coll=DL&CFID=151312215&CFTOKEN=26582949
instant city:  http://www.instantcity.ch/d/projekt/einleitung.htm

Evaluation

The researchers for this project conducted their evaluation both by objectively quantifying the limitations of the system as well as by having users test and give subjective feedback.
Their quantified evaluation described the whole system, such as limitations on how far the ZeroN may suspend from the solenoid, how fast ZeroN may move before it is dropped, or the maximum angle it may be it before the magnetic flux is too weak and the ball is dropped.  These limitations are not due to power restrictions for the magnet, but rather heat restrictions.  Too much current through the solenoid makes it start to melt.  In addition, the system only supports one ball at the moment.  These were simply gained from objective measurements.
The researchers obtained qualitative information for several different applications that used ZeroN, such as an architectural modeling program, a program to illustrate Kepler's law, and a trippy magnetic ping-pong game.  The most pressing issue was that there was a noticeable latency between the user setting ZeroN's position and the magnet refreshing to keep it there.  This caused confusion.

One-sided Discussion

From what I've read, this is the first time anyone has tried to create a magnetically suspended user interface.  The potential is there, but at the moment, the system needs to be expanded to include multiple ZeroN balls, and possibly decrease the variability in the position of ZeroN, to give it a more smooth feel.