Korn U, Rav-Noy Z, Shtrikman S, Zafrir M
Med Prog Technol. 1980 Apr;7(1):41-4.
In certain biological and medical applications it is important to measure and follow temperature changes inside a body or tissue. Any probe inserted into a tissue causes damage to tissue and distortion to the initial temperature distribution. To minimize this interference, a fine probe is needed. Thus, thin film technology is advantageous and was utilized by us to produce sensitive probes for these applications. The resulting probe is a small thermocouple at the tip of a thin needle (acupuncture stainless steel needle, approximately 0.26 mm in diameter and length in the range 5-10 cm was used). The junction was produced at the needle's tip by coating the needle with thin layers of insulating and thermoelectric materials. The first layer is an insulating one and is composed of polyacrylonitrile (PAN) and polymide produced by plasma polymerization and dip-coating respectively. This layer covers all the needle except the tip. The second layer is a vacuum deposited thermoelectric thin layer of Bi-5% Sb alloy coating also the tip. The third layer is for insulation and protection and is composed of PAN and polyimide. In this arrangement the junction is at the needle's tip, the needle is one conductor, the thermoelectric layer is the other and they are isolated by the plastic layer. The probe is handy and mechanically sturdy. The sensitivity is typically 77 microV/degrees C at room temperature and is constant to within 2% up to 90 degrees C. The response is fast (less than 1 sec) the noise is small, (less than 0.05 degrees C) and because of the small dimension, damage to tissue and disturbance to the measured temperature field are minimal.
在某些生物学和医学应用中，测量并跟踪身体或组织内部的温度变化非常重要。任何插入组织的探头都会对组织造成损伤，并使初始温度分布发生畸变。为了将这种干扰降至最低，需要使用精细的探头。因此，薄膜技术具有优势，我们利用它来生产适用于这些应用的灵敏探头。所得探头是位于细针（针灸用不锈钢针，直径约0.26毫米，长度在5至10厘米范围内）尖端的小型热电偶。通过在针上涂覆绝缘和热电材料薄层，在针的尖端形成结点。第一层是绝缘层，分别由通过等离子体聚合和浸涂法制备的聚丙烯腈（PAN）和聚酰亚胺组成。该层覆盖除尖端外的整个针。第二层是真空沉积的Bi-5%Sb合金热电薄层，也覆盖尖端。第三层用于绝缘和保护，由PAN和聚酰亚胺组成。在这种结构中，结点位于针的尖端，针是一个导体，热电层是另一个导体，它们被塑料层隔开。该探头使用方便且机械坚固。在室温下，灵敏度通常为77微伏/摄氏度，在高达90摄氏度的范围内，灵敏度变化不超过2%。响应速度快（小于1秒），噪声小（小于0.05摄氏度），并且由于尺寸小，对组织的损伤和对测量温度场的干扰最小。
