project is rapidly evolving, and documentation is out-of-date
almost as soon as it is written. We are in the process of a major
web-site redesign, which will make the publishing and maintenance of
project information even easier.
The MIThril project FAQ attempts to answer the most common
questions we receive regarding the MIThril project; if you have a
question that you don't see answered here on our web site, please send
mail to MIThril@media.mit.edu.
What is MIThril?
MIThril is a next-generation wearables research platform developed by
researchers at the MIT Media Lab. The goal of the MIThril project is
the development and prototyping of new techniques of human-computer
interaction for body-worn applications. Through the application of
human factors, machine learning, hardware engineering, and software
engineering, the MIThril team is constructing a new kind of computing
environment and developing prototype applications for health,
communications, and just-in-time information delivery.
The MIThril hardware platform combines body-worn computation, sensing,
and networking in a clothing-integrated design. The MIThril software
platform is a combination of user interface elements and machine
learning tools built on the Linux operating system. For more
information see the MIThril project overview
page for more information
Where does the name "MIThril" come from?
The name MIThril comes from the imaginative fiction of
J. R. R. Tolkien. It was coined in the book, The Hobbit,
which was first published in 1937, and later used in his Lord of
the Rings trilogy. In these stories, mithril is the
Elvish name of a metal (also called "silver steel" or "true silver")
with near-magical properties of strength, beauty, and lightness. This
metal was worked by the Dwarves into intricate ring-mail armor tunics,
light in weight and comfortable enough to be worn constantly, yet
unobtrusive and nearly indestructible. Frodo, the protagonist and
hero of the Lord of the Rings, wears a mithril tunic under
his traveling clothes; not even his companions know of its existance
until at a critical moment in the story it stops an Orc spear, saving
Frodo's mithril tunic is the inspiration and metaphor for the
MIThril project; our goal is to create technology that is light
weight, unobtrusive, reliable, and always doing its job.
Why do you have all of those wires?
Why isn't the body bus wireless?
What about using Bluetooth?
What about some other wireless protocol?
We've been hearing about Bluetooth's immanent availability for at
least the last four years. As of early 2002, we know of no readily
available, viable Bluetooth (or alternative) solution for on-body
But even given a workable wireless solution for body networking, you
must still power everything, and having a seperate battery for each
device poses some significant problems. (see below for an explanation)
Even if the power problem were not an issue, wireless data links raise
privacy concerns; Near-field body-lan type solutions that don't "leak"
much do not have the required bandwidth, and higher-bandwith wireless
is trivially subject to eavesdropping. Strong cryptography would
probably be needed to make a wireless body-lan private, and this would
impose additional computational (and thus power) overhead.
What is really needed is a short-range low-power ad-hock peer-to-peer
wireless networking protocol that could support device/resource
discovery, authentication, and transparent data encryption. This
would ideally be implemented as a single chip solution and consume on
the order of 10mW in active transmission mode. If anyone has a
solution like this, please contact us.
Why do you consolidate your battery power?
Seperately powering each component would result in significantly
reduced uptime or significantly increased system weight. (This results
from the non-ideal properties of batteries, but a full discussion is
beyond the scope of this FAQ).
Seperate batteries also impose increased demands on the user to
monitor and charge each battery seperately. The consolidated design
allows the user to keep the system up indefinitely by hot-swapping the
four system batteries.
Why not use notebook computer motherboards instead of the
Brightstar or CerfBoard?
Why not use an IPAQ or other modern PDA?
Most notebook computers use an x86 based architecture that maximizes
compatibility with conventional desktop computers but is not
particularly power efficient or flexible in the hardware interface.
Our choice of single-board industrial computers is driven by our need
for flexibility, small form-factor, and low power consumption.
The BrightStar ipEngine1 consumes on the order of two Watts (as
compared to almost ten times this much for a typical notebook
computer) and includes an on-board FPGA that provides an extremely
flexible hardware interface. The CerfBoard is very small,
significantly faster, and even more power efficient. It also provides
a built-in CF connector and 10-base Ethernet, as well as serial ports
and GPIO pins.
Most consumer electronics devices, be they PDAs or notebook computers
or cell phones, are engineered to maximize ergonomics and minimize
component count. This makes them decidedly difficult to "hack" or
repackage. We use these devices mostly for applications where
we can simply plug them in as-is.
I can't find the schematics and plans you keep promising -- where are they?
We are finally starting to put up document packages for MIThril
hardware; Check out the MIThril
hardware design page. Also, be sure to look at the MIThril
Construction section on our wiki.
What about MIThril software?
We are also starting publish our MIThril software as well; you can
find the code in our MIThril Code
Do you sell MIThril kits?
MIThril is a research architecture, not a product. There are no kits
or assembled units available for purchase. However, we hope to
document the MIThril design well enough that a sufficiently motivated
and technically able person could reconstruct our work from scratch,
and to make this as easy as possible.
When will MIThril units be commercially available?
Perhaps never. It is possible that one of our sponsors or some other
interested party may choose to use our published specifications and
plans as the basis for a commercial product; if this ever happens, you
can be sure we will make that information available here.