Preparation Of Urchin-like Microstructure-contained Polymer Composites And Their Wearable Diagnosis And Treatment Performance

Wearable electronic sensors have attracted extensive attention in multifunctional electronic skins,personalized health monitoring,intelligent human-machine interaction,and smart medical treatment.However,it is still challenging to simultaneously achieve excellent sensing performances with high sensitivity,rapid response,low detection limit and outstanding cycling stability for full-scale human healthcare detection.At the same time,traditional wearable electronic devices are lack of the further timely medical treatment capability after human healthcare monitoring and smart medical diagnosis.Furthermore,various wearable electronic devices exhibited a mechanical mismatch with the skin for poor wearing comfort,thus hindering their promising applications in human healthcare monitoring and accurate disease diagnosis.Here,inspired by the highly sensitive sensing capability of human skin microstructure,we fabricate an urchin-like microstructure-contained polymer composites and wearable sensors,demonstrating excellent sensing performance with reliable photothermal capability for full-scale human healthcare detection as well as the efficient diagnosis and treatment of diseases such as elbow arthritis.（1）The polybuthlene adipate-contained polyurethane（PBAPU）elastomer matrix is successfully obtained with polybutylene adipate（PBA）as soft segment,4,4-diphenylmethane diisocyanate（MDI）as hard segment and1,4-butanediol（BDO）as chain extender,exhibiting outstanding tensile strength（18.87 MPa）,high stretchability（1200%）and comparable elastic modulus（1.7 MPa）to human skin.The wild chrysanthemum pollen grains were assembled on the polyimide（PI）tape,and the inverse concave microstructure template was prepared by casting polydimethylsiloxane（PDMS）on the PI tape,and the PBAPU matrix with urchin-like microstructure was obtained through casting PBAPU elastomer matrix on the concave template.Finally,the MXene nanosheets were coated onto the as-prepared urchin-like sensing microstructure and the PBAPU/MXene composite was prepared.（2）The multifunctional electronic sensor with good flexibility and compliance was fabricated by face-to-face assembling the PBAPU/MXene elastomer matrix with urchin-like microstructure and an interdigitated electrode-coated PBAPU elastomer substrate.The stress concentration and the significantly increased contact area and conductive path could be obtained between the urchin-like microstructure and the bottom electrode under external pressure,leading to the effectively improved sensing sensitivity.The sensor exhibited excellent sensing performance(high sensitivity(up to 784.02k Pa^-1),broad working range（up to 300 k Pa）,low detection limit（2.8 Pa）,fast response time（9 ms）and reliable cycling stability（15000 times）)for human motions monitoring（such as elbow bending and swallowing）and tiny electrophysiological signals detection（such as electrocardiogram（ECG）signal and electromyography（EMG）signal）.（3）The PBAPU/MXene composite with excellent photothermal conversion capability could be employed to wrist/elbow arthritis treatment.The 2D MXene nanosheet can achieve up to～100%photothermal conversion efficiency.By exposing to an 808 nm near-infrared（NIR）light irradiation,the PBAPU/MXene composite could provide reliable photothermal capability with rapid heating rate(from room temperature to 54.5℃within 80 s at NIR light power density of 0.50 W/cm^-2),controllable temperature regulation and excellent photothermal stability,showing great potential in accelerating the blood circulation and significantly relieving pain and stiffness for realizing efficient arthritis disease diagnosis and medical treatment.