posted on 2019-08-15, 12:33authored byBushara Fatma, Ritamay Bhunia, Shashikant Gupta, Amit Verma, Vivek Verma, Ashish Garg
Propelled by the
development of the Internet of things and other
low-power devices such as in health care or sensing applications,
there is growing emphasis on development of energy harvesting devices
based on piezoelectric and triboelectric harvesting. We demonstrate
a highly flexible and transparent triboelectric nanogenerator (TENG)
prepared by incorporating maghemite (γ-Fe2O3) fillers in polyvinylidene fluoride (PVDF) with polyethylene terephthalate
(PET) as a triboelectric counterpart for potential application in
powering wearable electronic devices. Addition of γ-Fe2O3 fillers in the PVDF matrix results in a power output
with an average open circuit voltage of 250 V and short circuit current
of 5 μA, which is substantially higher than that from only-PVDF-based
TENG. With manually applied force, the lightweight TENG device (area
∼14.5 cm2 and weight ∼1 g) can induce a maximum
power output of 0.17 mW with a power density of 0.117 W m–2. In addition, this device is extremely robust with excellent long-term
stability for approximately 3000 s. We harvested biomechanical motion
in the form of slow and fast foot movement by attaching this device
to the sole of footwear. Moreover, the TENG device could continuously
supply enough power to light up 108 light-emitting diodes (LEDs) connected
in series, without the use of a capacitor and has potential applications
in self-powered wearable and portable electronics obviating the use
of batteries. Moreover, this device is shown to harvest energy from
the rotary pump to charge a 1 μF capacitor to a value of ∼30
V in just 90 s. In addition, a thick magnetic γ-Fe2O3/PVDF nanocomposite film was also successfully tested
as a magneto-triboelectric nanogenerator (M-TENG) in noncontact mode
showing potential for harvesting of the stray magnetic field.