Table 1 Comparative Summary of Bioelectronic Systems Based on Key Functional Features, Enabling Materials, Advantages, and Challenges
From: Materials strategy and device fabrication for stable closed-loop bioelectronics
Type | Ref | Biosignals | Device strategy | Mechanical property | Advantage | Limitation | Ref |
|---|---|---|---|---|---|---|---|
Wearable | Patch type | Monitoring electrophysiological signals on the skin surface | Flexible patch | Flexible | Skin-conformal, lightweight | Limited durability, no self-healing | |
Ultrathin patch | Ultraflexible | High skin conformability | Fragile under strain | ||||
Stretchable patch | Stretchable | Allows motion with minimal signal noise | Limited durability, no self-healing | ||||
Self-healing patch | Stretchable and Self-healing | Extended lifespan, durability after damage | Material complexity, slower healing at low temperature | ||||
Implantable | Probe type | Recording electrophysiological signals from internal organs or tissues | Microelectrode array | Rigid/Flexible | High spatial resolution | Mechanical mismatch with tissue | |
Soft microelectrode array | Soft conformable | Reduced inflammation, better biocompatibility | Fabrication complexity | ||||
Rigid probe | Rigid | High spatial resolution | Mechanical mismatch with tissue | ||||
flexible probe | Flexible | Easy insertion, better tissue integration | Risk of micromotion-induced damage | ||||
Stretchable probe | Stretchable | Tissue-like compliance | Long-term reliability concerns | ||||
Patch type | Applied to the surface of internal organs for signal acquisition or stimulation | Flexible patch | Flexible | Easy to conform to organ surfaces | Poor integration over time | ||
Flexible cuff | Flexible | Useful for nerve wrapping, stable stimulation | May cause nerve compression | ||||
Stretahble patch | Stretchable | High conformability and minimal motion artifact | Mechanical fatigue | ||||
Stretchable, self-healing cuff | Stretchable and Self-healing | Damage tolerance, long-term implantation potential | Fabrication and encapsulation challenges | ||||
Adhesive | EMG | Adhesive hydrogel layer | Adhesive | Stable interface on set tissues | Mechanical failure with water infiltration | ||
Adhesive OECT film | Adhesive and Conformable | Conformal contact with moving muscles | Fabrication complexity | ||||
ECG | Silica nanoparticle-loaded hydrogel | Adhesive and soft | Displaces interfacial water | Limited mechanical integrity due to dissipative hydrogel | |||
NHS covalent adhesive hydrogel | Adhesive and soft | Long-term ECG signal acquisition | Mechanical fatigue over time | ||||
Catechol-modified adhesive hydrogel | Adhesive and Self-healing | Robust adhesion on cardiac tissues | Potential selling | ||||
ECoG | Catechol-modified adhesive hydrogel | Adhesive and Self-healing | Conformal contact and underwater adhesion | Potential selling | |||
Injectable hydrogel | Drug delivery | Injectable through in-situ gelation | Syringe-injectable, stretchable and conformable | Rapid in-situ gelation, stable adhesion, effective hemostasis, and adaptability to irregular tissues. | Limited potential for electronic device applications | ||
injectable thermo-responsive hydrogel | Syringe-injectable, stretchable and conformable | Shear-thinning injectability and magnetic-triggered hyperthermia enable localized, targeted drug delivery | Limited potential for electronic device applications | ||||
ENG, EMG, tissue prosthesis | Phenylborate-based dynamic covalent bonds, in-situ gold nanoparticle formation | Syringe-injectable, Stretchable, conformable, self-healable, adhesive | Superior conductivity, self-healing, and robust mechanical integrity enable effective nerve &muscle reconnection, tissue repair, and closed-loop rehabilitation integration | Difficult to interface with conventional electronic devices | |||
ENG | In situ curing of a silicone-silver composite | Syringe-injectable, Stretchable, conformable, adhesive | Minimally invasive, durable, and biocompatible neural interface enabling reliable signal transmission | Difficult to interface with conventional electronic devices | |||
Injectable self-deployable mesh patch | Myocardial infarction treatment | Shape-memory cryogel | Syringe-injectable, Stretchable, conformable, self-deployable | Minimally invasive, shape-memory-enabled patch delivery enhances conductivity and promotes cardiac tissue repair | Lacks intrinsic adhesion and precise targeting is challenging | ||
Atrial Fibrillation Elimination | Mesh design, double-network (PVA/PEDOT:PSS) | Syringe-injectable, Stretchable, conformable, self-deployable | High conductivity, durability, and shape-memory ensure secure, long-term biocompatibility | Lacks intrinsic adhesion and precise targeting is challenging | |||
LFP recording | Ultrathin gold/polymer mesh device | Syringe-injectable, Stretchable, conformable, self-deployable | Ultrathin, macroporous mesh enables minimally invasive injection, rapid tissue conformity, and stable, inflammation-free chronic EEG monitoring | Challenging precise targeting, risk of deployment failure | |||
Electrophysiology of single RGCs | Noncoaxial intravitreal injection of mesh device | Syringe-injectable, Stretchable, conformable, self-deployable | Minimally invasive injection yields conformal retinal interfacing for stable, long-term RGC monitoring | Challenging precise targeting, risk of deployment failure | |||
Neural recording & electrical stimulation, Intracranial temperature & pressure monitoring | Compressed injection of mesh device | Syringe-injectable, Stretchable, conformable, self-deployable | Elastic expansion ensures conformal cortical contact for high-resolution multimodal monitoring and stimulation | Challenging precise targeting, risk of deployment failure | |||
Pysiological sensing | PLCL-PLGA mesh device | Syringe-injectable, Stretchable, conformable, self-deployable | Biodegradable shape-memory mesh enables non-surgical, conformal interfacing with high-fidelity monitoring and reduced long-term risks | Challenging precise targeting, risk of deployment failure | |||
Intrinsic-force-actuated deployable patch | ECoG | Fluidic pressure-driven eversion | Intrinsic-force-actuated deployable, Stretchable, conformable | Minimally invasive fluidic actuation enables gentle, conformal unfolding with real-time feedback for precise, large-scale neural recording | Mechanical mismatch with tissue, Lacks intrinsic adhesion | ||
Origami pre-folded design, Fluidic pressure-driven eversion | Intrinsic-force-actuated deployable, Stretchable, conformable | minimally invasive injection and controlled unfolding for large-area, stable high-resolution ECoG recordings | Lacks intrinsic adhesion | ||||
thermal-triggered in-situ expansion using shap memory alloys | Intrinsic-force-actuated deployable, Stretchable, conformable | Precise electrode placement, and minimal-trauma deployment for scalable, effective ECoG acquisition | Lacks intrinsic adhesion | ||||
ECG monitoring and pacing | 3D-printed PAA-PU/PEDOT:PSS, thermoformed balloon catheter | Intrinsic-force-actuated deployable, Stretchable, conformable, adhesive | Robust 3D-printed bioadhesive, stable sensing, and superior charge injection capacity | Limited channel |
