Fully Biodegradable Microsupercapacitor for Power Storage in Transient Electronics

Abstract

In this work, the authors report materials, fabrication strategies, and applications of biodegradable microsupercapacitors (MSCs) built using water‐soluble (i.e., physically transient) metal (W, Fe, and Mo) electrodes, a biopolymer, hydrogel electrolyte (agarose gel), and a biodegradable poly(lactic‐co‐glycolic acid) substrate, encapsulated with polyanhydride. During repetitive charge/discharge cycles, the electrochemical performance of these unusual MSCs is dramatically enhanced, following from the role of pseudocapacitance that originates from metal‐oxide coatings generated by electrochemical corrosion at the interface between the water‐soluble metal electrode and the hydrogel electrolyte. Systematic studies reveal the dissolution kinetics/behaviors of each individual component of the MSCs, as well as those of the integrated devices. An encapsulation strategy that involves control over the thickness, chemistry, and molecular weight of the constituent materials provides a versatile means to engineer desired functional lifetimes. Demonstration experiments illustrate potential applications of these biodegradable MSCs as transient sources of power in the operation of light‐emitting diodes and as charging capacitors in integrated circuits for wireless power harvesting.

Bioresorbable Materials on the Rise: From Electronic Components and Physical Sensors to In Vivo Monitoring Systems

“…Bioresorbable passive components (e.g., resistors, inductors, antennas, capacitors, diodes) have also been proposed either to complement active components (i.e., transistors) toward the realization of more complex circuits (e.g., antennas in radio frequency (RF) circuits), or to be used as transducers (e.g., heaters) in biomedical applications (e.g., antibacterial therapy).…”

“…In 2017, Lee et al reported on a fully biodegradable micro‐supercapacitors (MSCs) with high electrochemical performance. Fe, Mo, or W (about 300 nm thick) were used as electrode materials and current collectors, agarose gel with NaCl salt as hydrogel electrolyte (150 µm), PLGA (about 15 µm thick film) was used as supporting substrate, and polyanhydride as encapsulating material.…”

Metal Oxide and Hydroxide–Based Aqueous Supercapacitors: From Charge Storage Mechanisms and Functional Electrode Engineering to Need‐Tailored Devices

“…Thus, the capability to heal mechanical failures induced by the deformations would provide another innovative way to recover supercapacitor functionality. [178] Copyright 2017, John Wiley and Sons. Restorable and biodegradable supercapacitors.…”

Materials, Mechanics Designs, and Bioresorbable Multisensor Platforms for Pressure Monitoring in the Intracranial Space

“…Immediately after implantation, surrounding biofluids begin to hydrolyze and dissolve the constituent materials, as an intrinsic feature of the bioresorbable designs. A significant challenge is that bioresorbable encapsulation layers based on most polymers (poly(lactic‐ co ‐glycolic acid) (PLGA), [ 22 ] silk fibroin, [ 9,20 ] collagen, [ 23 ] and polyanhydride [ 14 ] ) and inorganic materials (silicon dioxide, [ 14,24 ] silicon nitride, [ 24 ] and various metal oxides [ 25 ] formed by chemical or physical vapor deposition) do not perform well as biofluid barriers to prevent premature and/or uncontrolled degradation of the active elements. Recent reports demonstrate promising results with ultrathin layers of silicon dioxide formed by thermal growth on the surfaces of silicon wafers (t‐SiO 2 ).…”