# Lego2Nano

Do-it-yourself atomic force microscope

The LEGO2NANO challenge aimed to develop, build and exploit an atomic force microscope (AFM) at an affordable price (below $500) for Chinese middle schools. To put this in perspective, traditional AFMs costs over$100,000, and even educational models are typically priced in excess of \$20,000. These microscopes are a very-high-resolution type of scanning probe microscope that can produce resolutions on the order of fractions of a nanometer, well below the optical diffraction limit, hence allowing to visualize structures such as DNA molecules or pollution particles. Hence, their potential as a learning tool is great, but the elevated price has prevented their adoption in educational settings. Therefore, the Lego2Nano Challenge sought to realize the educational potential of this micropscopy technique by addressing the cost barrier to adoption and involving students in the construction of the micrsocope, by aiming at a deployment as a pedagocical do-it-yourself (DIY) engineering project.

To achieve these goals, in 2015 our team of engineers and researchers travelled to Beijing and Shenzhen in China, to work at Tsinghua University and the Shenzhen Open Innovation Lab on the development of a cheap do-it-yourself atomic force micrsocope.

Our team of engineers and researchers

During our team in China, we developed a 3D printable structure to house the microscope, used a piezoelectric element and hacked a DVD laser to control and track an AFM tip as it moves through the surface of the sample, designed and built a circuit board to control these components, and used an Arduino Nano to operate the microscope. This DIY AFM was designed so that students could build the microscope themselves using commonly available electronic components and a 3D printer.

In addition to this, we built a citizen science platform to study air pollution. First, we developed a protocol to collect pollution particles using DVD disks after removal of their protective layer. Then, using the DIY AFM microscope, students could visualize the air pollution particles trapped in the DVD surface, and upload these to an online crowdsourcing platform. By gamifying the whole experience, students were incentiviced to upload images and participate in their analysis. Then, the data could be aggregated to study trends in the geotemporal characteristics of air pollution, not only in terms of concentration (e.g. PM2.5), but also in terms of the morphological characteristics of these pollution particles.