Fully transient stretchable fruit‐based battery as safe and environmentally friendly power source for wearable electronics

Abstract

Power sources with good mechanical compliance are essential for various flexible and stretchable electronics. However, most of the current energy storage devices comprise of hazardous materials that may cause environmental pollution when improperly disposed. We show the first example of a stretchable, yet fully degradable battery made from nontoxic and environmentally friendly materials such as fruit‐based gel electrolytes and cellulose paper electrodes. The battery exhibits an areal capacity of 2.9 μAh cm−2 at 40 μA cm−2, corresponding to a maximum energy density around 4.0 μW h cm−2 at 56 μW cm−2 power density. The biomaterials constituted battery shows good mechanical tolerance to twisting, bending, and stretching while powering various electronic devices when combined with kirigami. Importantly, the entire battery disintegrates readily in phosphate buffered saline/cellulase solution. We integrate the “green” battery with various sensors in wearable healthcare devices for pulsation sensing and low‐noise surface electromyography applications.

Sustainable wearable energy storage devices self‐charged by human‐body bioenergy

“…The Mg battery was thin, flexible, and reliable for powering wireless epidermal sweat sensors and the heart rate sensor, suggesting the promising future of Mg batteries to serve as wearable power sources. Wang et al imparted the stretchability to their “green” Mg battery (lemon juice as the electrolyte) by introducing the kirigami structure design 45 . The Mg battery can endure bending, twisting and stretching, paving the way for the fabrication of “green” wearable power sources.…”

Transforming wood as next‐generation structural and functional materials for a sustainable future

“…That's why they have limited applications in biomedical systems, energy storage devices, catalytic support, pollutant removal, biosensors, artificial muscles, thermal insulations, and actuators. [77][78][79][80][81][82] In recent years, research has focused on developing nature-friendly and cost-efficient H&As using top-down methods directly from wood. Processing wood into H&As is relatively straightforward.…”

“…Smart textiles are evolving advanced functional materials due to their thermal and electrical conductivity. 78,164,165 These textiles are prepared by incorporating conductive nanomaterials like carbon nanotubes and graphene with cotton, hemp, or synthetic materials. 166 Cellulose nanofibers have also been practiced for conductive textile applications through wet spinning, dry spinning, microfluidic spinning, and hydrodynamic alignment fabrication methods.…”

Realizing Stretchable Aqueous Zn–Based Batteries by Material and Structural Designs

“…Despite endowing stretchability to individual battery components, structural designs are also capable of enabling stretchability of rigid battery components by transforming them into stretchable configurations after adapting wavy (Figure 1E) (Mackanic et al, 2020a), fiber-shaped (Figure 1F) (Mo et al, 2020), or kirigami structures (Figure 1G) (Wang et al, 2021), to redistribute the external forces on the specific component unit. Of note, by applying these promising battery configurations, stretchable batteries could be realized based on the stretchability of supporting elastomers to redistribute force, without strict requirements on the stretchability of the battery components.…”