Wearable machines have the potential to revolutionize industries by providing human-like agility and balance to operators. The document discusses the history of wearable machines from early military exoskeletons in the 1950s designed to give soldiers superhuman strength to current developments that allow direct control of machines through brain interfaces. A concept for a wearable machine called Mecha-MAX is presented, which is a powered exoskeleton suit that can lift over 3,000 pounds and mimic human movements, with the goal of amplifying a person's physical capabilities.

1. Wearable machines are poised to potentially revolutionise
the industry. With human-like agility and balance, they
could ensure operators are always dressed for success
A dictionary can be a most
useful tool. The word
‘wearable’, quite simply, is defined
as ‘capable of being worn on the
body’.” The definition of ‘machine’
is a bit more complex: ‘an apparatus
using or applying mechanical power
and having several parts, each with
a definite function and together
performing a particular task’.
How about ‘vehicle’? Apparently,
it’s ‘a thing used for transporting
people or goods, especially on land’.
For an industrial vehicle, these
‘goods’ could be containers, pallets
or dirt, or even the implements used
in the performance of specialised
work. And there is no requirement
for a ‘vehicle’ to have wheels or
tracks for getting around, opening
the door for some new and intriguing
possibilities as to the form futuristic
industrial vehicles might take.
A wearable vehicle would
therefore be a machine that is
essentially worn and mimics the
movements of the human body. A
truly wearable machine would
therefore be almost human-like in
the manner of its operation and its
function. Its movement would be
controlled by the natural motions of
the human operator – not by a
steering wheel, accelerator pedal and
joysticks. If the operator walks, the
machine will walk; and if the
operator reaches, the machine
reaches along in parallel. The
wearable machine is, in fact, a
human exoskeleton, a robot that –
potentially – greatly expands the
physical capabilities of the operator
while maintaining human agility,
co-ordination and balance.
Over the following pages, we take
a look at wearable machines and their
development over the past 50 years,
followed by a look at actual wearable
machines of today and perhaps of
tomorrow. It has taken a full half-
century for this technology to mature
to the point of practical application
– and it appears that it is now, finally,
on the cusp of practical success.
Origin of the species
It may come as no surprise that
there have been two driving forces
behind the development of wearable
machines. For the first, imagine a
military planner in the 1950s with
dreams of an army of mechanised
soldiers, each capable of walking or
running over rough terrain while
carrying hundreds – possibly
thousands – of pounds of weapons
and armour. With superhuman
strength and speed, a single soldier
could hold his own against dozens
of regular, human-only soldiers, so
imagine what a division of soldier-
robots could accomplish!
Accordingly, it was the military,
particularly the US Army, that made
initial forays into the concept at the
height of the Cold War.
The other driving force responsible
for kick-starting the technology falls,
interestingly, at the opposite end of
the application (or moral) spectrum.
Imagine an individual with limited
walking ability, perhaps due to polio.
Now imagine a powered exoskeleton
designed to assist the physically
handicapped so that they can
amplify their own limited muscular
power and walk like an able-bodied
person, or even carry a load heavier
than an able-bodied person could
manage. A confluence of developing
technology and imaginative
thinking during this same mid-
century period resulted in this, the
second driving force, behind the
development of wearable machines.
General Electric walking truck
In 1966, the US Army contracted
General Electric to create a
‘cybernetic walking machine’ to
help infantry troops carry heavy
equipment quickly over rough
iVTInternational.com September 2009
Mecha-MAX could be the
answer to heavy lifting
tasks in confined areas
GET-INTO
GEAR
steveN casey, ergonomic systems design
iVTInternational.com September 200932 33
THE WEARABLE MACHINE
DigitalartbyPixelInside:pixel@meganet.lt

2. terrain. The result was the GE
Walking Truck, a giant beast over
11ft tall that was operated by a
single human occupant who
‘walked’ with hands and feet while
perched inside the cab.
Sensors on the hand and foot
mountings drove hydraulic valves
on external leg-like appendages.
With moderate skill, but with some
effort, an operator could walk at
5mph, pull a Jeep out of a mud hole,
climb over large obstacles, and push
1,000 lb (454kg) across a concrete
floor. With integral force feedback
built into the controls, and the
overhead and see-through skeletal
cab, the operator had sufficient
feedback from the massive mechanical
legs to walk forward and backward,
turn around, and even balance on
two diagonal legs. A Walking Truck
simulator enabled operators to
practice ‘walking on all fours’
without the cost and hazards of
running the actual machine.
So, you might wonder, whatever
happened to the GE Walking Truck?
This was a true quadruped robot,
and a successful research project at
that, but there were some serious
problems along the way. First, its
power was external, provided by
long hydraulic hoses and a distant
power source. Obviously, this would
not work in the battlefield until an
internal power source could be
developed, something that never
happened within the scope of the
US Army’s project.
Second, operating the Walking
Truck was quite taxing on the
operator – not quite the energy-saver
that was envisioned by the US Army.
And third, without today’s compact
sensors and microprocessors, the
only sense of balance in the walking
truck was the sense of balance in the
human operator. Hence, the whole
contraption had an unnerving
tendency to fall over, delivering, no
doubt, a serious jolt to its operator
who, moments before, had been a
full 11ft above the ground!
The GE development engineers
were no dolts, however: check out
the side ‘rollbars’ on the model in
the US Army Transportation
Museum if you ever happen to be in
the vicinity of Fort Eustis, Virginia.
The GE Hardiman man-amplifier
The next stop on our tour is GE’s
Hardiman, which began development
in 1965. The Hardiman’s possible uses
iVTInternational.com September 2009 35iVTInternational.com September 200934
Construction machinery is the natural
outgrowth of man’s desire to increase his
own physical ability to dig, lift, and carry;
to clear land and improve his environment.
So in many ways, this equipment is already
the wearable machine that is the subject of
this article. However the dream still exists
that will allow man to extend his ‘personal’
abilities in a more direct fashion, and recent
developments in several arenas have moved
this desire closer than ever to reality.
In addition to the many advancements
mentioned elsewhere in this feature, one
of the most promising developments for
translating fine motor skills into machine
motion is the work being carried out by Dr
John Donahue at Brown University in the
USA – he has devised a way to link a
person’s brain to a computer. ‘Braingate’
involves implanting a computer chip in the
brain that can read a person’s thoughts
and translate them to activate a machine
or device.
What is even more incredible is that it
has been proven that this can be done by
just placing a device on the subject’s scalp,
so we are not far away from being able to
wear a hat or helmet that is hooked up to a
machine and being able to direct it purely
through our thoughts.
Indeed, researchers at the University of
Pittsburg are already working on this next
lift, and transport materials weighing up to
several thousand pounds is required.
That brings us to the concept illustrated
here. Mecha-MAX, developed by
Montgomery Design International, is a
wearable machine capable of increasing
mans’ individual abilities to perform many
of the tasks listed above.
MAX is a fully articulated powered,
titanium/aluminium exoskeletal suit that is
capable of lifting up to 1,200kg (3,000 lb)
under the right conditions. MAX can walk
on his tracks in a relatively human fashion,
climb over debris, or, crouched in the
transport mode, he can run on tracks at
speed of up to 35km/h. Using his built-in
gyroscope capability – an outgrowth of the
Segway – he can even stand on his ‘toes’ to
extend his reach, or traverse stairs and
particularly difficult terrain. Direction
control is also achieved in much the same
way as the Segway, and at higher speeds,
turns would be very similar to cross-country
skiing. In addition to the gyroscope, MAX’s
drivetrain modules contain the v.10 nano-
titanate batteries and electric motors that
allow him to run continuously for four to
six hours depending on the workload.
To protect the operator from falling
objects, MAX has lightweight graphite/
kevlar shields over exposed flesh and a
fixed helmet with an integral structure. As
an option, it can even be air conditioned to
provide additional comfort and the safety
of a transparent face shield if required.
To facilitate entry/egress, MAX can extend
the power modules upward and rotate
downward to kneel, allowing step-in
operator access. Additionally, this position
allows for lifting smaller or flat objects with
his rubberised fingers and hands. Optional
devices could also be attached in place of
the hands, e.g. large clamps, or even saws
and hammers for serious deconstruction.
MAX’s dimensional layout gives one a
feeling for the scale of the machine, and
although a near-9ft tall ‘man’ with a 14ft
wingspan would be quite imposing, the
overall footprint is akin to a commercial
lawnmower; still relatively compact in the
construction equipment world. MAX is still
some way from fruition, of course, but
looking at the strides being made in this
field, we don’t think he’s all that far off.
Contact: Gregg Montgomery,
Montgomery Design International, Inc.
contact@montgomerydesign.com
www.montgomerydesign.com
+1 630 971 9700
step, devising an experiment where a
monkey was restrained, yet through a chip
implanted in his brain, was able to feed
himself using a mechanical robot arm that
he almost seemed to accept as his own.
This is a sign of embodiment that would
indicate the brain’s ability to easily accept
this type of transference.
A final bit of technology that may help
close the loop on all of this is the Audeo.
This is a device invented by the Ambient
Corporation that attaches to the throat just
above the larynx, and captures the
electrical signal between the brain and the
vocal chords and synthesises speech or
turns thoughts into action. Combining this
type of sensor with the Braingate
technology and the developments already
discussed, leads us pretty rapidly to the
kinds of machines and devices previously
only seen in sci-fi movies.
But realistically, what sort of jobs could a
wearable machine perform in today’s
sophisticated marketplace? Several things
come to mind: search and rescue activities
involving earthquakes, remote servicing of
heavy equipment, un/loading cargo in
tight spaces such as ships, airplanes and
trucks, extraction in vehicle accidents…
basically anything involving work in
extreme environments, where only a human
can go, but where the ability to demolish,
The Wearable Machine
- Future Concept
Gregg Montgomery MDI
top RIGHT: Research
prototype of the GE
Walking Truck – all
11ft and 3,000 lb of it
RIGHT: Hardiman’s
left arm assembly
demonstrated by
Philip Croshaw. The
full machine was
designed to handle
heavy loads in areas
that preclude the use
of forklifts
THE WEARABLE MACHINETHE WEARABLE MACHINE
MechaMAX concept and design by Montgomery Design International:
www.montgomerydesign.com

3. iVTInternational.com September 200936 iVTInternational.com September 2009 37
included loading ordinance onto
aircraft, oilfield work, heavy
construction, nuclear materials
handling, and even use in space.
The machine was intended to have
tremendous carrying and lifting
power with which it could transport
its own nuclear shielding if used in a
radioactive environment.
With the weight of the machine
and any load distributed down via
the exoskeleton legs directly onto
foot platforms on which the user’s
feet were strapped, the Hardiman
was designed to let a user easily lift
loads of 1,500 lb (680kg). Like a true
exoskeleton, it was designed to sense
the movements of the user, mimic
those movements in the machine,
and provide limited force feedback
so the effectiveness of movements
could be judged naturally.
But when all the pieces were put
together as a full system, things did
not work quite as planned. Co-
ordinated use of the exoskeleton parts
was not possible, and resulted in
violent and uncontrolled motions
that could be lethal to the operator.
Imagine having your own leg strapped
to a device capable of bending it in
any direction with thousands of
pounds of pressure! Interestingly, it
was never actually operated by a
human being while fully powered-
up because of the dangers involved.
Focus then shifted to refining the
operation of one of the arms
independent of the whole machine,
and these efforts were reasonably
successful. A single arm eventually
was able to lift 750 lb (340kg),
certainly an impressive feat, but the
arm itself weighed 0.75 ton, about
twice the weight of the load. With
hindsight, it is apparent that the
complex psychomotor functions
performed by the human central
nervous system could not, in a
certain sense, be replicated by the
limited logic and data-processing
capabilities available in the 1960s.
Hardiman was impressive, but very
much ahead of its time.
HAL, a modern exoskeleton
Focused on developing a human
exoskeleton for aiding physically
disabled or elderly individuals,
Professor Yoshiyuki Sankai of the
University of Tsukuba has led the
development of HAL (Hybrid
Assistive Limb), a relatively light,
electric-powered exoskeleton that is
now in production and available for
rental in Japan.
Unlike the GE Walking Machine,
Hardiman, or exoskeletons that are
discussed later, HAL’s inputs from
the human operator are from bio-
electric signals. HAL was developed
during the last decade, but there is
nothing new about detecting an
EMG signal from human muscle.
In layman’s terms, the EMG is an
electromyogram signal emitted from
human muscle, detected from
electrodes that are taped to the skin
at specific points on the arms and
legs. These faint signals are fed to a
fast computer, also part of the HAL
exoskeleton, which recognises the
signals and the likely intended
action of the user. The computer
then directs the motorised joints of
the exoskeleton into action and
assists the movement of the human.
So, instead of sensing the physical
movement of the user’s arms and
legs as other exoskeletons do, HAL
uses EMG signals from the muscles
to sense the user’s intended motions.
HAL’s exoskeleton elements are
strapped to the user’s limbs, and
battery-powered electric motors at
the joints provide the assistive forces
required for standing, walking and
other movements. With its light
frame and relatively moderate force
assistance, HAL might be seen as the
antithesis of the formidable
Hardiman exoskeleton of the 1960s.
The company Cyberdyne was
formed near Tokyo in 2008 to mass-
produce HAL exoskeletons. In Japan,
a waist-down suit, essentially a pair
of legs, or one leg, is available for
monthly rental, and a full-body suit
has been under development for a
number of years. HAL suits come in
three sizes – small, medium and large.
Power assist suit and the HULC
Another approach has been taken by
researchers at Janawaga Institute of
Technology, who began development
of the Power Assist Suit in 1990.
Unlike HAL, the Power Assist Suit is
a semi ‘soft’ exoskeleton that
provides force assistance with
multiple pneumatic, air-driven
bladders and baffles. Its primary
function is to aid in the lifting and
transfer of medical patients. The suit
is reported to cut lifting efforts by at
least 50%. Unlike the latest Robot
Suit HAL, the HAL-5, the Power
Assist Suit has not reached full
commercialisation.
In 2000, the US Defense
Advanced Research Projects Agency
(DARPA) undertook what has
become a US$75 million effort to
develop powered exoskeletons for
the military. The program has met
with considerable success, through a
great deal of creative engineering
and also great leaps in technology
over the past decade.
Among the first recipients of
DARPA research funds was the
University of California at Berkeley’s
Robotics and Human Engineering
Laboratory. Based on the successes
of the lab’s efforts, the company
Berkeley Bionics was formed and
licensing agreements were made to
cover exoskeleton technologies that
had been developed. Defence giant
Lockheed Martin has established a
licensing agreement with Berkeley
Bionics regarding ‘several applications
of its exoskeleton technology’.
The University and Berkeley
Bionics team has focused much of
their effort over the past few years
on lower-extremity exoskeletons
that enable a user to carry
substantial loads at relatively high
rates of speed over rough terrain, if
necessary. Their first groundbreaking
project was BLEEX (Berkeley lower
extremity exoskeleton), the ‘first-in-
the-world load-carrying lower
extremity exoskeleton’. BLEEX has
been followed by additional load
carrying exoskeletons: ExoHiker,
ExoClimber and HULC, with the
latter having received perhaps the
most attention.
While wearing the HULC lower-
extremity exoskeleton, a user can
carry up to 200 lb (90.7kg) with no
impediment, and transport this load
for up to 20 hours depending on the
number of batteries loaded. A burst
speed of 10mph can also be achieved.
Unlike the HAL exoskeleton, which
comes in three sizes, HULC adjusts
to fit soldiers ranging in height from
5ft 4in to 6ft 2in (162.5-188cm).
There are also attachments for lifting
heavy objects and a kit for carrying a
combat casualty patient. The system
itself weighs about 53 lb (24kg), and
it can be put on or removed in a
matter of seconds.
Berkeley Bionics has obtained
US$2 million from the US National
Institute of Standards and Technology
to develop the system to aid the
neurologically or physically impaired.
Sarcos XOS
Of all of the groups funded by the
DARPA Human Performance
Augmentation seed money, perhaps
Sarcos, the offshoot of a research
engineering group at the University
of Utah, has produced the most
impressive exoskeleton to date.
Defence giant Raytheon has recently
acquired Sarcos, and it is now
known as Raytheon Sarcos.
The result is the Sarcos XOS, a full-
body exoskeleton consisting of 30
actuators, cables, hydraulic cylinders,
high-pressure hydraulic lines, sensors
and a computer. The goal of the XOS
is to make any effort effortless. For
example, when an XOS wearer pulls
down with 200 lb of force, the system
applies just enough power to the
right elements of the exoskeleton so
that the user feels minimal force. At
the same time, surprising levels of
user agility are maintained.
Sarcos, like all other exoskeleton
developers, has struggled with the
area of power, and most testing has
been performed with a tether and an
external power source. Sarcos was
recently awarded a two-year, US$10
million grant to move forward with
final designs for XOS and develop
compact portable powerplants for
the machine. It has recently tested
units powered by self-contained
turbine generators running jet fuel
for up to 24 hours of operation.
The future of the practical
wearable machine, it would seem, is
just around the corner. [Actually, it’s
just over the page – Ed.] iVT
For further information:
Steven Casey,
5290 Overpass Rd, Suite 105,
Santa Barbara, CA 93111, USA
Tel: +1 805 683 6610
Email: scasey@
ergonomicsystemsdesign.com
Web: www.ErgonomicSystems
Design.com
main image: The Sarcos
XOS tested by software
engineer Rex Jameson. The
suit amplifies his strength
and endurance so much
that he can shoulder press
200 lb up to 500 times
top: Rear view of the
exoskeleton
above: Close up of the
exoskeleton’s knee and
foot
above left: The
Power Assist Suit is
reported to reduce
lifting effort by half
below left:
Designed to help the
elderly and infirm,
the HAL suit is now
available for monthly
rental in Japan (Prof.
Sankai, Cyberdyne Inc,
Univ. of Tsukuba)
below: The incredible
HULC: designed to
promote endurance, it
enables 200 lb loads
to be carried for up
to 20 hours (Lockheed
Martin)
THE WEARABLE MACHINE THE WEARABLE MACHINE
On the Web
Sketches, videos and links:
www.iVTinternational.com/wearable