Wide-Sensing-Ranged PANI:PEO Piezoresistive Pressure Sensor Array in Pressure Distribution Monitoring on Cervical Discs Under Neck Flexion

Recently, phubbing has led to a significant increase in neck-related diseases such as cervical disc (CVD) herniation. CVDs experience a typical pressure of approximately 200 kPa in the upright position, which increases dramatically with the degrees of flexion. Thus, there is a high probability for patients who have undergone the cervical artificial disc replacement surgery to have the revision surgery owing to the inappropriate postures. Herein, a highly sensitive piezoresistive pressure sensor array with a wide sensing range of up to 1000 kPa, utilizing polyethylene oxide (PEO) as the sensing membrane and polyaniline (PANI) as the conductive filler, is proposed to real-time monitor the pressure distribution on CVDs. The optimal PANI doping concentration in PANI:PEO composite films was determined to be 0.1%, which demonstrated excellent sensitivity of 0.279 kPa
^-1
, a high coefficient of determination (R
²
) of 0.959, and a short relaxation time of 0.72 s of the PANI:PEO piezoresistive pressure sensors. To accommodate the sensor array within the limited space of the cervical vertebrae, the electrode size of the devices was significantly reduced to less than 100 μm to realize a 2×3 PANI:PEO piezoresistive pressure sensor array. The fabricated pressure sensor array effectively monitored the pressure distribution on CVDs in a cervical spine model with a full cervical spine and dual cervical vertebrae under different flexion angles, holding favorable potential to avoid further CVD herniation after the cervical artificial disc replacement surgery.