Inorganic materials based on silicon, germanium, zinc oxide, and dielectrics present

features as bioresorbable electronics, semiconductivity, and also can be dissolved in

water. These parameters are considered as an important advantage in the context of the

applications of biocompatibility and electronic because many biological processes involve

ionic fluxes in an aqueous environment and the transduction or transformation of ionic

signals into electronic ones [8]. An inorganic biomaterial can present different temporal

linkers as an electronic device, and their dependence and response in the tissue will

define their biocompatibility. In the same way, there are other important inorganic bio­

materials related with the coordination polymers together with nanostructured materials,

which have emerged as a solution for the current challenges in the preparation and ap­

plication of structures that show fine crystals without impurities, high specific surface

area, hierarchical pores, and thermic stability.

On the other hand, several metal oxides have been reported in the literature as pro­

missory materials for bioelectronics applications. Among a lot of these oxides, zinc oxide

(ZnO) has attracted considerable attention due to its exceptional properties such as low

cost, high abundance, and wide bandgap [9]. The typical structure of ZnO consists of two

forms: wurtzite and zincblende; however, wurtzite seems to be the most stable under

ambient conditions. Besides, its polar ions (Zn²⁺ and O²⁻) make this solid interesting for

photocatalytic applications and besides as excellent material in piezo electronics. In the

same way, ZnO nanoparticles have been recently used for bioelectronics applications

because they can be used as the active sites in several biological events defining the

sensitivity and stability of the device where they will be applied. Different shapes of this

oxide (from nanorods, nanotubes, nanosheets, nanodiscs, nanowalls, nanoflakes) present

advantages with respect to the number of active sites providing fast electronic transfer

and also creating an extra surface area with enhancing in its mechanical and electronic

properties [10]. Similarly, indium-gallium-zinc oxide (IGZO) has been fabricated as

Schottky diodes on a thiol-ene/acrylate shape memory polymer (SMP) that can endure

mechanical strain with minimal to no loss in electrical performance [11]. In particular,

IGZO has gained much attention due to its high mobility, low-temperature process

compatibility, and insensitivity to visible light. In general, inorganic materials containing

inert and semiconductors amorphous oxides have been a point of especial interest for

bioelectronics. Among the properties of this kind of material are synthetic routes of low-

cost, low-temperature, bias-stress stability, and processability.

Among the existing technologies, nanomaterials have been converted into an important

topic for researchers of different areas. Fundamental differences are related to the size of

nanometer-scale objects and their functions. In general, there are two ways to synthesize

materials in the nano-scale: Bottom-up and top-down; the selection of one method over

the other depends on the final requirements of the material and will define the synthetic

strategy. Many nanomaterials have been reported to be active for implants, electronic

devices, and sensors with exceptional mechanical, thermal, and optical properties. Several

nanomaterials can fill the required properties to be used as bioelectronics, among them,

inorganic nanoparticles that present large surface area, are inert, and have high me­

chanical resistance.

2.2.2 Organic Bioelectronics Materials

Bioelectronics materials based on organic components represent the next step in the

development of a high-efficiency biotic/biotic interface since they allow overcoming

limitations associated with flexibility, softness, and malleability, features required to

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Bioelectronics