problem associated with PI is that it has not Food and Drug Administration

compliant. However, PI has shown superior biocompatibility for long-term ap­

plications. Moreover, the coatings of stable oxide films such as Al2O3 over PDMS

have been shown to enhance the stability of such encapsulation layers.

Hydroxyapatite (HAP) coatings can be an excellent alternative over PDMS or

PI polymers as the compound is naturally biocompatible and is highly stable

under in-vivo conditions.

3. An essential aspect of self-powered technology is the miniaturization of the de­

vices. The miniaturization allows the devices to fit into compact spaces inside the

body, along with the added advantage that in the case of sensors, where accurate

monitoring of specific vital signs is necessary, the device’s bulkiness would lead

to measuring uneven stress. This would lead to a wrong interpretation of the

results. In addition, in the case of cardiac pacemakers, the maximum allowable

size is 16 mm × 16 mm, and its weight should be under 6 g. Thus, it is clear that

the quality and the expectancy of a patient’s life are significantly affected by the

miniaturization of the life-saving devices. Efforts are directed towards devel­

oping self-powered devices that are of the size of cells. However, such ambitious

projects will require a substantial amount of time.

The discussion clarifies that harvesting the energy from various daily mechanical activities

to power devices is an interesting construct and can potentially eliminate an age-old so­

lution relating to batteries. However, there are significant challenges, some of which have

been discussed at length in the previous sections. There is always a cost associated with

state-of-the-art technologies. To make the technology affordable for each person, significant

developments are yet to be made. For instance, in the case of PV cells, the cells are con­

sidered rigid and very expensive. Using organic PV has overcome the solution to both

issues. The concerns remain about the efficiency of the energy conversion of these cells.

Similarly, in the case of NGs, achieving a cost-effective method to manufacture TENG,

PENG, etc., is still a challenge for the researchers. In all these efforts, it has to be ensured

that biocompatibility is never compromised; the entire effort shall be rendered useless.

20.7 Conclusions

In this chapter, an effort to discuss emergent technology in the field of self-powered

devices has been made. Several technologies like the NGs, and PV cells have addressed

the need for alternative sources of power other than the traditional batteries. Some of

these technologies are at an advanced stage of development, and some of them have

delivered products that have helped clinicians save lives at critical junctions. The de­

velopment of self-powered technologies also promises to augment some of the already

existing technologies with a better lifetime, better functioning, and ease of implantation.

Cardiac pacemakers must be mentioned in the context, which is undoubtedly a versatile

device. The only limitation that can be thought of this device is its bulky battery, which

has a limited lifespan. Self-powered technology holds the potential to eliminate the as­

sociated drawbacks. However, despite these developments, there remain areas where the

significant thrust is the need of the hour. This chapter introduces the reader to the pos­

sibilities of such technologies and identifies some of the core areas where further research

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