## 4. Degradable Sensor Materials
### Degradable Polymeric Materials
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Categories** & **Materials** & **Typical Properties** & **Application Scenarios** \\ \hline \multirow{9}{*}{Polyester} & PLA & High mechanical strength, moderate & Intracranial pressure monitoring, \\  & & degradation cycle & cardiovascular device encapsulation \\  & PGA & High rigidity and rapid degradation & Orthopedic fixation monitoring, \\  & PLGA & Controlled degradation (weeks to years), & Tissue engineering scaffolds integrate \\  & PLGA & adjustable flexibility & sensors and multi-parameter \\  & PCL & Excellent flexibility and slow degradation & biochemical monitoring \\  & PCL & Excellent flexibility and slow degradation & Flexible hemodynamic sensors, \\  & (2–3 years) & self-powered ECG monitoring \\  & PHA & High biocompatibility and variable & Biodegradable electrode packaging, bio \\  & degradation cycles & signal monitoring \\  & PHB & High crystallinity and long degradation cycle & Bone repair monitoring and implantable \\  & P4 HB & High elasticity, moderate degradation cycle & Vascular stent sensor, soft tissue \\  & PLA-PCL & Balance strength and flexibility, adjustable & Multimodal sensor base, heart \\  & degradation cycle & valve monitoring \\  & PLATMC & High flexibility and moderate degradation cycle & Nerve conduit pressure monitoring, soft \\ \hline \multirow{9}{*}{Polyanhydrides} & PSA & Rapid degradation (weeks), surface erosion release & Short-term controlled drug release sensor, \\  & & Linear drug release and controlled degradation & postoperative inflammation monitoring \\  & & cycle (1–6 months) & Targeted therapy sensors, tumor \\  & & cycle (1–6 months) & microenvironment monitoring \\  & & Good thermal stability and non-toxic degradation & Stress monitoring and drug release feedback \\  & & products & of bone repair materials \\  & & Excellent flexibility and slow degradation & Vascular stent deformation monitoring, \\  & PTMC & (>2 years) & dynamic force sensor \\  & PPC & Good low temperature toughness, moderate & Low temperature environment for implant \\  & & degradation cycle (1–3 years) & device encapsulation and tissue \\  & & & engineering monitoring \\  & & Antibacterial, rapid degradation & Wound healing monitoring, infection \\  & & (weeks to months) & warning sensors \\  & & & \\  & Hyaluronic Acid & High water retention, promote cell migration & Soft tissue repair monitoring, dynamic \\  & & & analysis of joint fluid \\  & Sodium Alginate & Ion-crosslinked gelation, rapid & Injectable sensor carrier, \\  & & degradation (weeks) & Phi-responsive monitoring \\  & & & \\  & CMC & Good water solubility and high biocompatibility & Electrode paste substrate, degradable \\  & & Thermal gelability, moderate degradation & circuit board \\  & & cycle (months) & Drug sustained-release sensor, intestinal \\  & & & cyclic (months) \\  & & Strong film formation and rapid & Temporary encapsulation material, \\  & & degradation (weeks) & short-term physiological \\  & & & parameter monitoring \\  & PSA & Rapid degradation (weeks), surface erosion release & Short-term controlled drug release sensor, \\  & & & postoperative inflammation monitoring \\ \hline \multirow{9}{*}{Proteins} & Silk Fibroin & High mechanical strength and controlled & Flexible electrode base, neural \\  & & degradation cycle (3–6 months) & signal monitoring \\  & Collagen & Promotes cell adhesion and rapid & Skin sensors, dynamic monitoring of \\  & & degradation (weeks) & tissue regeneration \\  & Gelatin & Temperature-sensitive gelation, rapid degradation & Injectable sensor carrier, short-term drug \\  & & (days to weeks) & release monitoring \\ \hline \multirow{9}{*}{Other Synthetic Materials} & Polydioxanone & Good flexibility and moderate degradation cycle & Future tension monitoring, soft tissue \\  & & (6–12 months) & repair sensor \\  & & High elasticity, moderate degradation cycle & Myocardial strain monitoring, dynamic \\  & & (1–2 years) & tissue mechanics sensors \\  & PCLA & Balancing flexibility with degradation rate & Multimodal sensor integration, organ \\  & & (1–3 years) & transplant monitoring \\  & Materials & Thermosensitive gelation and degradation cycle & Injectable temperature response sensor and \\  & & are controllable & dynamic drug release monitoring \\  & (PLGA, variations in & Adjustable degradation rate and mechanical & Customized tissue engineering sensors, \\  & different proportions) & properties (weeks to years) & multi-parameter monitoring \\  & (PLGA, supplemental variant) & Rapid degradation (weeks to months), & Short-term postoperative monitoring and \\  & & & inflammatory microenvironment feedback \\ \hline \multirow{9}{*}{Natural derived materials} & Starch & Fast degradation (about 90 days), low cost & Temporary sensor encapsulation, gut \\  & & & microbial monitoring \\ \cline{1-1}  & Lignocellulose & Natural porous structure, & Degradation circuit board base, \\ \cline{1-1}  & & compostable degradation & environmentally responsive sensor \\ \cline{1-1}  & Nitrocellulose & High mechanical strength, controlled degradation & Microfluidic chip sensors, drug \\ \cline{1-1}  & & (months to years) & release monitoring \\ \hline \end{tabular}
\end{table}