According to a study published in Cyborg and Bionic Systems, recent advances in flexible bioelectronics have made significant progress toward seamless integration at bio-tissue-electronic interfaces.
E, elastic modulus; EEG, electroencephalography; ECoG, electrocorticography; WC, water content; COF, coefficient of friction; IOP, intraocular pressure; ECG, electrocardiogram; EMG, electromyography. Image Credit: Ming Wang, institute of Optoelectronics & Department of Materials Science, Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, State Key Laboratory of Integrated Chips and Systems (SKLICS), Fudan University
However, persistent obstacles such as foreign body response (FBR) caused by mechanical mismatch and signal instability under dynamic physiological settings remain key impediments.
By synergizing bioinspired chemical modifications with microstructural topology, we developed a self-healing bioadhesive interface that eliminates reliance on external stimuli, overcoming the physiological incompatibility of traditional rigid encapsulation materials.
Ming Wang, Study Corresponding Author and Professor, Fudan University
This three-layer material architecture combines: (a) catechol-functionalized polyurethane elastomer substrates inspired by mussels that have a modulus similar to brain tissue (<1 kPa); (b) conductive hydrogels crosslinked by dynamic borate ester bonds that have ultrahigh toughness (420 MJ/m³); and (c) MXene-silk fibroin composite anti-inflammatory coatings that scavenge reactive oxygen species (ROS) to counteract immune responses.
This multiscale design actively modulates macrophage polarization during early implantation and restores 90% conductivity within 48 hours post-mechanical damage.
Dr. Xiaojun Wu, Study Lead Author, Fudan University
The results of validation using rat cortical implantation experiments showed that the fibrous capsule thickness was reduced to one-third of that of conventional materials (28.6 ± 5.4 μm vs. 85.2 ± 12.7 μm), and that the electrophysiological signal acquisition was stable over 30 days (signal-to-noise ratio (SNR) of 37 dB vs. 15 dB for conventional Pt electrodes).
Under 100% tensile strain, the self-healing hydrogel maintained a conductivity of 1.2 S/cm and increased impedance by 8.7% after 10,000 mechanical cycles. The device outperformed commercial silicon-based Utah arrays in motion artifact suppression by 40% (RMS error <15 μV) and accomplished synchronized drug delivery (82% cumulative release over 72 hours).
“Microfluidics-assisted 3D printing enabled precise fabrication of vascularized conductive networks, achieving a curvature adaptation radius of 200 μm,” highlighted Wang.
Future efforts to include biomimetic mineralization layers to improve barrier performance are prompted by current limits, such as a 23% conductivity degradation after 28 days of biofluid immersion. This work advances the development of diagnostic-therapeutic implantable systems and establishes a fresh paradigm for adaptive brain interfaces by pioneering the combination of material chemistry intelligence with bioelectronic functionality.
The study's authors include Xiaojun Wu, Yuanming Ye, Mubai Sun, Yongfeng Mei, Bowen Ji, Ming Wang, and Enming Song.
The STI2030-Major Project (2022ZD0209900, 2022ZD0208601, and 2022ZD0208600), the Science and Technology Commission of Shanghai Municipality (22ZR1406400), the Shanghai Sailing Program (grant no. 21YF1451000), the State Key Laboratory of Integrated Chips and Systems (SKLICS-Z202306, SKLICS-Z202315), the Young Scientist Project of MOE Innovation Platform, and the National Natural Science Foundation of China (62204057, 62204204, U2341218, and 62104042) all provided support for this study.
Journal Reference:
Wu, X., et al. (2025) Recent Progress of Soft and Bioactive Materials in Flexible Bioelectronics. Cyborg and Bionic Systems. doi.org/10.34133/cbsystems.0192