| Summary: | ABSTRACT
Hariyadi. 2005. Bio-(Iight) Sensor Performed by Leaves of Puteri Malu {Mimosapudica L.). Biologi 4 (5): 315-324.
Observation has*been done to plant of Puteri Malu {Mimosa pudica L.) for their leaves movement for a bio-light sensor phenomenon as variation of light intensities illuminated to then-leaves at visible wavelengths. Common phenomenon observed from plant of Puteri Malu is their stems (called petiole) which will collapse immediately after touching or pressure or flame experienced to the plant and then back to normal after some times. Meanwhile, phenomeon for leaves movement in relation to changes of light intensities is not reported yet. The observation was carried out using an ultrasonic propagation technique. From the observation it was obtained a 'window of sensitivity' (WoS), i.e. the region of light intensities in which leaves will active to move. This region was observed from about 40 to 230 lux. For intensity less than 40 lux, the leaves will completely closed, whereas for intensities higher than 230 lux the leaves will open completely. Recovery time needed by leaves from closed to open completely, and vice versa were taken about 40 and 50 minutes, respectively. Therefore observation of leaves movement in relation to light intensities (petiole at a normal position) is considered new and further work could be improved for various applications such as environment indicator or military use.
Key words: puteri malu, biosensor, petiole, environment.
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