Converting infrared radiation in the form of heat into electricity is one of the interesting energy conversion approaches. This can be simply accomplished through thermoelectric effect with the well-known device called thermoelectric cooler (TEC). In this paper, we briefly overview TEC-based concepts, demonstrations, and products for converting heat into electricity. We then propose our own portable TEC-based heat-to-electricity converting module. Experimental proof of concept is also highlighted showing a promising output voltage of 5VDC and 0.224A suitable for low voltage applications. Future work relates to design optimization, engineering improvement, and testing in real world scenario.
Based on our research work in the last five years, this paper highlights our innovative optical sensing system that can identify and separate silkworm gender highly suitable for sericulture industry. The key idea relies on our proposed optical penetration concepts and once combined with simple image processing operations leads to high accuracy in identifying of silkworm gender. Inside the system, there are electronic and mechanical parts that assist in controlling the overall system operation, processing the optical signal, and separating the female from male silkworm pupae. With current system performance, we achieve a very highly accurate more than 95% in identifying gender of silkworm pupae with an average system operational speed of 30 silkworm pupae/minute. Three of our systems are already in operation at Thailand’s Queen Sirikit Sericulture Centers.
The embryo or germ of a rice seed is growing to the shoot and the root parts of a seedling. In the early stage, the
germinated embryo directly receives food from the endosperm. How healthy of the seedling can be physically predicted
by measuring the areas of the embryo and endosperm. In this work, we show for the first time how the embryo and
endosperm areas of a brown rice can be spatially measured. Our key design is based on the utilization of a tablet
equipped with our lens module for capturing the rice seed image under white light illumination. Our Windows-based
program is developed to analyze and separate the image of the whole brown rice into the embryo and endosperm parts
within 2 seconds per seed. Our tablet-based system is just 30×30×6 cm3
with 1 kilogram in weight, capable to easily
carry to perform in the field.
Dimensions of grains are important factors in evaluating the physical quality of the grains. In this work, we show for the first time that the thickness, the width, and the length of rice grains can be simultaneously measured. Rather than imaging rice grains only above from a two-dimensional plane, our key idea is to insert a tilt reflective surface on the measuring plane such that the side view of the rice grains can be observed at the same time. Demonstration from our prototype shows a very promising result in determining the thickness, the width, and the length of the rice grain with maximum values of 2.20 mm, 3.65 mm, and 10.27 mm, respectively. It offers a very high average resolution of 22 μm and a measured response time of 205 ms. Additional key features include low cost, low components count, and ease of implementation.
This paper describes the development of a fiber-optic confocal probe suitable to measuring the central thickness of highcurvature
small-diameter optical ball lenses. The confocal probe utilizes an integrated camera that functions as a realtime
apex-sensing device. An additional camera is used to monitor the shape of the reflected light beam. Placing the
instrument sensing spot off-center from the apex will produce a non-circular image at the camera plane that closely
resembles an ellipse for small displacement. By analyzing the shape of the reflected light spot, we are able to precisely
determine the focus point of the confocal probe relative to the apex point to better than 2-μm precision for ball lenses
with diameters in the range of 3 – 10 mm. The proposed confocal probe offers a low-cost alternative technique for
quality control of ball lenses during the manufacturing process.
We encourage primary school students in the grades 4-6 to challenge themselves on exploring light in everyday life. At the beginning, we bring in the critical-thinking approach where we use open-ended questions in applications of photonics around them. Later on, we engage them to our photonics lessons via our “Long Len” photonics kit. With our educational kit, we observe that most students in 21 schools from different parts of Thailand are amazed about photonics. They try to play with our kit in their ways, enjoy learning with their friends, and give us back many interesting questions. Based on their evaluations on our approach, 90-98% of them understand more about topics they already know. They also gain new knowledge and can see how it is applied to everyday life. The remaining percentage relates to students who are shy to interact with us.