Researchers from theGeorgia Institute of Technology和Hanyang University，韩国，已经开发了第一个aerosol jet printed(AJP) biosensor for wireless monitoring of blood flow.
In a study published in高级科学, the team have used a novel AJP technique to 3D print an implantable and stretchable electronic system. This maintains a circuit-free and low-profile design with enhanced readout distances, capable of监测大脑中的血流以进行动脉瘤治疗。
Implanted wireless monitoring devices
Wearable techrefers to smart electronic devices that can be worn or implanted in the body.3D printing has enabled new wearable devices such aselectronic second skins， 和智能面料. Furthermore, in combination with soft materials, stretchable and flexible devices likebiosensorshave been developed.
the functionality of these sensors depends heavily on their wireless monitoring capabilities which isenabled by rigid circuitry. Nevertheless, according to the researchers, rigid circuitry leads to incompatibility with soft tissues or blood vessels.
“The rigid electronics based on metals and plastics have a huge risk of thrombosis and flow disruption in a highly contoured blood vessel for monitoring of hemodynamics [dynamics of blood flow],” the study states.
用气溶胶喷射打印制造植入传感器
解决传统织物的缺点ation techniques,AJP was introduced to produce wireless implantable sensors. This technology allows for faster and reliable fabrication and scalable manufacturing via direct printing, digital designing, and optimized control.
In this study, the researchers developed a novel AJP approach for developing wireless stretchable electronics. Their biosensor utilizes polyimide as the dielectric layer and as a bottom supporting layer for a direct integration with a soft elastomer. The process starts with high precision 3D printing of four aligned layers, with ink composed of biocompatible silver nanoparticles and mixed polyimide (PI).
A small amount of of soft elastomer then connects the sensor to a medical stent. This seamless integration process enables the sensor to conform to the stent with high flexibility and stretchability. The resulting low-profile device can be deployed through conventional catheter procedures.
Wireless monitoring of hemodynamics
对于无线询问进行植入，研究人员采用了一种提供无电路设计的电感耦合方法。该读取方法在流动器系统中的传感器线圈和两个外部线圈中应用电感耦合原理来记录瞬态信号。
完成和优化传感器系统后，进行了体内实验。研究了最佳传感器线圈在通过空气，盐水和肉类的无线检测中无线检测中的性能。发现通过肉的最大读数距离为6厘米，达到大脑中血流动力学监测的范围。然后，在高度轮廓和狭窄的人类神经血管模型中测试了传感器的流速监测能力。the study adds:
“Collectively, this work shows the potential of the printed biosystem to offer a high throughput, additive manufacturing of stretchable electronics with advances toward batteryless, real-time wireless monitoring,”
the current limitation of this study is the integration of an implantable coil with the stent and sensor system to achieve a complete implantable package. Now, the team is developing methods for integration of an implantable, inductive coil with the existing stent and flow sensor.
未来的工作将涉及传感器系统的血液相容性和生物相容性测试。血液对传感器和可植入线圈的特性（例如线圈转弯之间的电容短路）的影响将进一步研究。
“Fully Printed, Wireless, Stretchable Implantable Biosystem toward Batteryless, Real‐Time Monitoring of Cerebral Aneurysm Hemodynamics”isco-authored by Robert Herbert, Saswat Mishra, Hyo‐Ryoung Lim, Hyoungsuk Yoo, Woon‐Hong Yeo.
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特色图片显示the design of a highly stretchable sensor via finite element modeling and comparison with the fabricated sensor. Image via Georgia Institute of Technology/Advanced Science.
