Haridas Chandran


Haridas Chandran



Synthesis and Characterization of Carbon based and Transition metal Quantum Dots


Fig 1: Experimental setup to synthesize CdSe Quantum Dots.

Students in the Robotics Automation and Design class will focus on designing and collecting equipment to build and conduct an experiment to synthesize Quantum Dots from carbon and transition metal based chemicals. The main purpose of this project is to kindle enthusiasm among high school students and create confidence that they can learn and synthesize these nanoparticles that are used in various industries namely medicine, engineering and technology.

Fig 2: CdSe Quantum Dots appearance under UV light.

Students will be getting materials namely, cadminum oxide, Oleic acid, selenium, trioctylphophine and octadene from Sigma Aldrich. They will also familiarize in using the equipment namely analytical balance, stirrere hotplate, syringe with needle to inject the solution in to the round bottomed flask, absorbance spectrometer and graduated pipets. To make selenium stock solution they will add 30 mg of Se and 5mL of octaecene to a 10 mL round bottom flask over a stirrer hot plate. Since Se is an inhalation hazard, this operation will be done in a fume hood. Students will also measure using syringe 0.4 mL of trioctylphosphine from its sure-seal bottle and add to the round bottom flask.

Once this stock solution is prepared, students will follow 7 steps to synthesize CdSe quantum dots (Fig 1). Once the quantum dots are kept under the UV light the fluorescence of the sample will appear as shown in Fig. 2

Fig 3: Medical Imaging of a rat.

Once the quantum dots are prepared they will use UV-Visible spectrometer in our lab to record the absorption spectra. From the absorption spectra they will measure the energy gap to find the particle size. These quantum dots have many applications in the medical field. It is used to find the presence of tumor in the body by injection the solution and scanning via UV light. This is shown in Fig.3 for the experiments in mice to find the presence of tumor in its body. Students will construct explanations from several scientific practices by writing a report and presenting at conferences.



VEX Robotics in Principles of Engineering Curriculum.


Fig 1: Different parts used for building a functional VEX robot.

Students in the Principles of Engineering classes will focus on designing and constructing a VEX robot that can be used performing tasks namely carrying, holding, pushing and ploughing an object to a designated place. The main objective of this project is to engage students in the area of Science, Technology, Engineering, and Mathematics in a fun manner and provide hands on opportunity to explore and experience it for themselves. This engagement will naturally encourages team work, problem solving and leadership in this young age. Students will use various components as shown in Fig 1, namely, steel base, motors, gears and using the principles in the unit materials and structure. They will also study regarding the statics, materials properties and material testing. During each stage of building they will understand the concept of simple machines concepts namely inclined plane, wedge and screw and the mechanical advantage of these simple machine techniques incorporated in this robot. They will check the operational of the control systems namely machine control, fluid power control by connecting the brain of the robot and writing codes. This will enable them to learn different computer languages namely, C, C++ and prepare themselves to enter the field of computer engineering for post secondary education. Finally they connect the controller to the robot and operate the robot through the controller as shown in Fig. 2 Once the students design and construct the robot, the final product be as shown in Fig 3.

Fig 2: Robot Brain and Controller

Fig 3: Constructed Robot

Using this robot students will collect the data on kinematics and perform statistical analysis. They will also collect data from testing the material and obtain properties of various components. They will also collect data on the gear ratio required for specific actions. Completion of this project will allow students to go for VEX robotic competition within the state or out of state. This robot can also be used by the JROTC group to showcase their talent at the Army USA skills competition. Experience learnt from designing, construction and coding by the Principal of Engineering students can help JROTC students to perform well in their competition. Students will construct explanations from several scientific practices by writing a report and present at conferences.

All sessions by Haridas Chandran