In this paper, a method for the focal length measurement of Microlens-array (MLA) is introduced. The
measuring setup is composed by monochromatic, condenser, collimator, MLA, microscope and CCD
sensor. An experiment was performed using a MLA whose focal length is about 8 mm and a GUI based
on Matlab software was developed to analyze the image gathered at the vertex and the focus by the
clarity of digital image processing technology. The measuring uncertainty of this method is about
0.8% and this method introduced in this paper can finish tens of microlens array measurement at a
single shot. Compared with traditional technology for MLA measuring, this method not only has a
preferable precision but also super efficiency.
Microlens-arrays have been used in many fields; it's difficult to measure the focal length by traditional method. This
paper introduces a new technique for the focal length measurement. Place the grating close-by the focal point and make
the +1 order and 0 order rays diffracted from the grating interfering, from the number of interference stripe we can get
the grating defocus, ulterior finish the focal length testing. In this paper, we enumerate the expression between the
defocusing and the interference stripe number. At the same time, we make an experiment to prove the feasibility. The
experiment result shows that this technique has a higher testing accuracy and efficiency as opposed to traditional method.
We designed and fabricated a new portable passive DMFC stack with its volume significantly reduced. Its high
efficiency and load regulation performance were also demonstrated through experiments, and its stability seemed to be
very good. We achieved a maximum power density of 3.9mW/cm2 with a 2M methanol concentration under ambient
conditions. This performance is better than that of a conventional DMFC. The volume of the 10-cell series connection
DMFC stack is only 42mm x 42mm x 40mm. Due to its stable performance and easy fabrication, this structure is believed
to be applicable for portable small-scale DMFC stack.