Biomedical applications of MOEMS are limited only by the humankind imagination. Precision measurements are minute amounts of biological material could be performed by optical means with a remarkable accuracy. Although available in medical laboratories, such analyzers are making their way directly to the users. Such an example is the test kit to detect the existence of cardiac enzymes in the blood stream. Apart from the direct users, the medical personnel will make use of such tools given the practicality of the kit. In a large proportion of patients admitted to hospital suspected of Acute Myocardial Infarction (AMI), the symptoms and electrocardiographic changes are inconclusive. This necessitates the use of biochemical markers of myocardial damage for correct exclusion or conformation of AMI. New cardiac-specific markers have recently been introduced into the detection of AMI. The cardiac troponins, because of their extraordinary high specificity for myocardial cell injury, have gained particular interest.
Experimental setup involves the use of a rectangle shaped AFM cantilevers, optical lenses, laser source, oscilloscope and a charged coupled device (CCD) to detect the cantilever deflection. When specific biomolecular binding occurs on one surface of a microcantilever beam, intermolecular nanomechanics bend the cantilever, which can be detected optically. Based upon the above concept, troponin I was detected optically by depositing it on the microcantilever containing anti-troponin I. The laser beam was directed on the cantilever and the deflection noted on the CCD.
The control of environmental conditions, such as temperature, pressure, and humidity, are important in many applications ranging from bio-medical to space exploration. Proper humidity control is also important in the conservation of organic materials. Therefore an accurate and sensitive method to characterize the moisture content of the particular environment is of valuable importance.
This paper proposes a humidity sensitive polyimide material as a fiber optic sensor for humidity measurements. The spectral analysis and the intensity of transmitted light through the polyimide sensor will represent the humidity measure. The paper also presents the absorption characteristics of the proposed humidity sensitive material.
The experimental values on the spectral shift and light intensities are measured at different humidity conditions. This paper will also present the feasibility study for using the proposed fiber optic sensor for humidity measurements.