Highly Sensitive Capacitive MEMS for Photoacoustic Gas Trace Detection.

An enhanced MEMS capacitive sensor is developed for photoacoustic gas detection. This work attempts to address the lack of the literature regarding integrated and compact silicon-based photoacoustic gas sensors. The proposed mechanical resonator combines the advantages of silicon technology used in MEMS microphones and the high-quality factor, characteristic of quartz tuning fork (QTF).

Hoatzin nestling locomotion: Acquisition of quadrupedal limb coordination in birds.

The evolution of flight in birds involves (i) decoupling of the primitive mode of quadrupedal locomotor coordination, with a new synchronized flapping motion of the wings while conserving alternating leg movements, and (ii) reduction of wing digits and loss of functional claws. Our observations show that hoatzin nestlings move with alternated walking coordination of the four limbs using the mobile claws on their wings to anchor themselves to the substrate. When swimming, hoatzin nestlings use a coordinated motion of the four limbs involving synchronous or alternated movements of the wings, indicating a versatile motor pattern.