Table 2 Summary of All Electrode Performance Parameters

Single-Shank Electrode

Tungsten wire guide

PI

128

Cross-sectional area:

100 μm²

25 μm/

100 kΩ

—

8 months

¹⁴

Open Sheath Flexible Electrode

PI

64/128

15 μm thick

1.2 mm wide

30 μm/

33~200 kΩ

—

25 days

¹⁵

Filamentous Electrode

SU-8

8/4

50 µm/10 µm wide

1 mm thick

-/-

—

At least 4 months

²¹

NeuroRoots

Parylene

32

Single wire 7μm wide

1.5μm thick

15 μm/

40kΩ

4.1

At least 7 weeks

¹⁷

Planar Mesh Electrode

SU8-guided

SU

16/32

Interconnect 10 μm wide, 1μm thick

15 μm/

100 kΩ

—

Lifespan of adult mouse

²⁹

Cylindrical Mesh Electrode

Syringe injection

Hexagonal boron nitride

32

1–1.2 mm wide

<10 μm/

—

9–11

1 year

^30,34

Neuron-Inspired Mesh Electrode

SU-8

16

Dendrites and soma of pyramidal neuron-like cells

—

—

3 months

³¹

Semi-flexible Utah-like Electrode

Direct implantation

PI

16

8 mm × 8 mm

—

—

6 months

^35,36

Microfluidic Semi-flexible Utah-like Electrode

Pneumatic impact

Si

12

13 mm × 8 mm

-/

374.32 kΩ

3.5

³⁷

Fully Flexible Origami Electrode

PLGA coating

PI

33

<20 µm thick

400 µm²/

-

—

At least 2 days

³⁹

Neural Fringe Electrode

PEG coating

PI

1024

Single microelectrode filament diameter

3 × 1.5 mm²

10 mm/

50 kΩ

—

At least 6 weeks

⁵⁴

Bilayer Silk-Parylene Electrode

Silk fibroin layer rigidification

Parylene

4

250 μm wide

40 µm/

9.4 kΩ

—

—

⁵⁵

3D Nanomesh Electrode

Quick freezing

SU8

13

—

>7

—

⁶⁰

Liquid metal electrode

Liquid metal injection

PDMS

3

30 μm thick

40μm wide

-/

21.4 kΩ

—

—

⁶¹

Bacterial Cellulose-Based Electrodes

Adhered to brain surface

Bacterial Cellulose

10

Each electrode channel 20 μm wide

-/

55.6 kΩ

—

—

⁷⁴

Hydrogel Hybrid Electrodes

Water absorption softening

Hydrogel matrix (PAAm-Alg)

3

Waveguide diameter 105.9 µm

—

—

6 months

⁷⁸

Microporous Drug-Releasing Electrodes

—

PI

4

—

—

—

5 weeks

⁹²

Biomolecule-Modified Electrodes

PEG coating

Si

33

3 μm thick

-/

0.7 MΩ

16 weeks

⁹⁹