Spectroradiometry of LEDs arrays for cell culture irradiation

• Grant number: 14/23867-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2015
• End date: February 28, 2017
• Field of knowledge: Physical Sciences and Mathematics - Physics
• Principal Investigator: Luciano Bachmann
• Grantee: Jaqueline Ramos Sousa Fernandes
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

LEDs (Light Emitting Diodes) are semiconductors with higher energetic efficiency and can operate with lower voltage and electric current. These characteristics give advantages over conventional illumination. The LED applications are diverse, since signaling (low power) up residential illumination and also are employed for phototherapy in biological applications (high power). Microtiter plate for cell culture are employed together UV, visible or infrared irradiation in diverse phototherapy research. The LED emission that can be employed for such irradiation must to be characterized through radiometric and spectroradiometric quantities. Such kind of characterization is necessary because it is well know that LED emits lower as the unit becomes older, there is expected variation between the well of the microtiter plate resulting in a non-homogeneity of the irradiation matrix of the plate. To measure quantities such as spectral power of the LEDs, spectral irradiance of the irradiated surface, becomes necessary the employment of an appropriate instrumentation as sphere integration and calibrated detectors. The present project aims the characterize spectroradiometrically LEDs that will employed in biological applications. With this characterization is possible to prepare a protocol for regular calibration and gauge LED matrix that aims to be employ in phototherapy applications. The literature and the previous work in the Laboratory of the present research group expect to see some characteristics that area intrinsic for LEDs systems such thermal effects, aging effects and variability between lots; but is necessary to measure the amplitude of these effects over the final irradiance and power of the matrix. (AU)