The PowerWalk
™
Kinetic Energy Harvester
Bionic Power* makes wearable technology for charging batteries.
The PowerWalk™ Kinetic Energy Harvester delivers uninterrupted, potentially
life-saving power in the field for communications, navigation and optics.
As well, the PowerWalk can reduce the overall electrical system
weight by reducing the need for extra batteries.
The PowerWalk enables users to produce 10-12 watts of
power as they walk. The light-weight harvester is designed
to generate electricity from the natural action of walking,
in much the same way regenerative braking works in
hybrid cars. With every stride, the harvester’s on-board
microprocessors analyze the wearer’s gait to determine
precisely when to generate maximum power with the
minimum metabolic cost.
Over the course of an hour, walking at a comfortable
pace, users wearing a harvester on each leg can
generate enough power to charge up to four
smart phones.
Mission-critical Benefits:
• Reliable power for unlimited duration
• Reduced fatigue on downhill
•Reduced need for soldiers to carry backup batteries
•Fewer logistical tail challenges with battery
replacement and resupply
•Significant cost savings
•Increased mission flexibility, duration
and potential effectiveness
•Smaller environmental
footprint
* PowerWalk and the Bionic Power mark are trademarks of Bionic Power Inc., registered in the U.S. and other countries.
PowerWalk Features
Unimpeded Mobility: the biomimetic
design provides limitless flexion into full
squat while allowing the unit to fold up
for compact transport.
Intelligent Response: the PowerWalk’s
onboard microprocessors analyze walking
gait, speed and terrain to determine the
best timing and resistance to generate the
maximum amount of power with the least
amount of user effort.
Dual Mode Connectivity: when plugged
directly into a battery, the system will
act as a battery charger, using SMBus for
charge control. When plugged into a soldier
power manager, the system will act as an
alternative DC power source, using SMBus
to communicate power capacity.
Reduced Metabolic Cost and Fatigue:
taking advantage of the natural braking during
downhill walking, test results measured a
20% drop in metabolic cost and a 28% drop
in muscle activity, which can reduce soldier
fatigue significantly.
Vastus Medialis
0.14
0.12
STANCE
SWING
EH OFF
EH ON
iEMG Change
=-28%
0.1
Voltage (mV)
Anatomically Accurate: the patent-pending
four-bar hinge follows the natural biomechanical
motion of the knee by tracking both femoral
rollback and tibial rotation during knee flexion.
0.08
0.06
0.04
0.02
0
0
0.2
0.4
0.6
08
1
1.2
1.4
Time (s)
Adjustable Sizing: the three available size
options, with adjustable length shells and
straps, ensure the PowerWalk can fit the 5th to
95th percentile of the soldier population.
High-efficiency Power Conversion: the
gearbox, generator and power conversion
were designed from the ground up for
optimal efficiency.
Sealed Construction: built for all soldier
missions, no matter how harsh the environment.
How Harvesting Works
The PowerWalk is designed to generate
electricity from the natural action of walking,
in much the same way regenerative braking
works in hybrid cars.
swing
swing
flexion
stance
stance
stance
swing
extension flexion extension
swing
flexion
In the PowerWalk’s high-efficiency system, a
gearbox transmits the power produced to a
generator which harvests energy during these
regions of the gait. Then, state-of-the-art
electronics are employed for power conversion
and model-based, gait-phase-detection
algorithms intelligently optimize energy harvesting
to minimize work from leg muscles. This can
reduce fatigue and metabolic effort, and extend
the duration and effectiveness of the mission.
Velocity
(rad/s)
5
0
-5
Torque
(Nm)
25
0
-25
Power
(W)
50
0
-50
0.0
0.2
0.4
0.6
0.8
1.0
Time (sec)
When we walk, our muscles perform ‘positive’
work to propel us forward. This work is done
by the muscles around the ankles and hips.
Our muscles also do ‘negative’ work, acting as
brakes to slow down our limbs or absorb impact.
The muscles around the knees primarily perform
this negative work. The PowerWalk harvests
the energy generated by the knee joints during
negative work (shown as shaded areas in the
graph above), which not only assists the muscles
with braking but also generates electricity
without noticeably adding to the metabolic cost
of the user.
PowerWalk Specifications (system contains two harvesters)
Parameter
Target (Q3 2017)
Power (level at 5.0 km/h)
10 W
Power (downhill 15% grade)
25 W
Power (uphill 15% grade)
4W
System Weight
1.8 kg
Output Voltage* 10 - 32 V
Max Output Current (into battery)
5A
Max Output Current (into power manager)
2A
Communication Protocol
SMBus v1.1
Acoustic Noise
< 40 dBA SPL @ 1m
Doffing Time
<5s
TRL6-7
Sealing IP67 / 1m immersion
Connectors
Glenair Mighty Mouse Series 807
(Can be adapted as required.)
*Depending on battery type / power manager.
Projected Development Plan
ID
TASK NAME
1
Ruggedization and Manufacturing
Development
2
Trial System Availability
3
Volume Manufacturing
Development & Verification Testing
4
Estimated Production Readiness
2016
Q3
2017
Q4
Q1
Q2
2018
Q3
Q4
Q1
Q2
2019
Q3
Q4
Q1
LEARN MORE: Today, Bionic Power is focused on developing the PowerWalk for military use and
will begin multi-unit field trials with the U.S. Army and U.S. Marine Corps in 2017. The remaining
first-run production units will be available on a first-come, first-serve basis. In the
future, we see our walk-recharge technology being used in disaster zones
and remote work sites, and by consumers in recreational,
About Bionic Power
emergency preparedness and backup applications.
Contact Yad Garcha with field trial inquiries:
Bionic Power makes wearable
technology for charging batteries. The
[email protected]
™
Kinetic
Energy Harvester enables users to
PowerWalk
1.778.330.4217
produce power as they walk. Wearing a harvester on each leg, users
produce an average of 10-12 watts of electricity which, over the course
of an hour-long walk, can charge one to two smart phones. The walk-recharge
capability of the PowerWalk reduces user requirements to carry backup batteries, as well as
the need for battery resupply in the field. Development and testing of the PowerWalk is supported by
the U.S. Army and U.S. Marine Corps as well as the Canadian Department of Defense.
Bionic Power. Walk. Recharge.
2661 Lillooet Street, Vancouver, BC V5M 4P7, Canada
www.bionic-power.com
[email protected] | 1.778.729.0680
D0079-03_Technical Brochure