Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Measurement of the temperature distribution on curved surfaces is performed in several applications and devices including electronic appliances, aerodynamic systems, automobiles, and medical systems and devices. Such measurement may be achieved with a flexible temperature sensor or sensor array, which may use silicon or metal strips as sensing elements on a flexible substrate, for example, a polyimide substrate.
Use of silicon as a sensing element entails the use of several expensive processing steps associated with typical silicon processing. Also, such silicon processing may suffer from known issues such as silicon etchants that may have a deleterious effect on the polymer substrates. Accordingly, for successful processing, further expensive processing steps may be used including, e.g., encapsulation, a process of sandwiching the sensing element with a protective layer resistant to environment. The protective layer protects the sensing element from moisture, oxidation, etc. which may damage the sensing device/element.
Similarly, using metal strips as sensing elements on a substrate also entails expensive processing and material. Apart from these cost issues, metal sensing elements may not be reliable because of the mismatch of thermal expansion between the metal sensing element and the polymer substrate on which the sensing element is deposited. Metal sensing elements have also been known to have a restricted operational temperature range and lack tunability for sensitivity.