BUILDING A HIGH POWER POCKET SIMPLE MICROSCOPE

By: Alvaro Amaro de Azevedo (Brazil) – 10 November 2006
Converted to html format Jan. 2015 (mol smith)

Preliminary Introduction by mol smith
This article was originally published a good few years ago (as a PDF file). I believe it to be an interesting article to encourage people rising to this hobby to consider they do not need to rely solely on purchased expensive technology. Self-reliance, curiosity, and well... just being someone who doesn't run with the crowd - these can make a person an innovator. We need people just like that. We need new generations who just don't go with the status quo, who, instead surpass their previous generations with their new minds and ingenuity. Life is about work, play, and self-exploration for everyone. What we do differently... these are often the things which define us!

1. Introduction

The idea of building a portable high power simple microscope accompanies most of my projects especially because the whole construction setup can easily be made in small sizes and be stored in small boxes. However, the construction of a pocket microscope is rather more challenging hence, it has to be small enough to slip inside a pocket, containing all what takes to en-sure a good performance including a suitable illumination system. The main constrain for me, however wasn’t any of these requirements but just one simple and practical aspect, the maintenance of the lens system protected against dirties and particles one generally carries within the pocket. If the lens collects dust, fibers or dirties, the performance of the objective will be se-verely compromised. This project represents a solution for this problem and is totally based in easy to find materials.
 

2. Designing the Microscope

The concept here is to build the microscope in a small box that can stay closed by a snap action and can easily be open when required. The illumination setup would consist of a 3 V Lithium battery connected to a white LED and a switch. The beam of white light is collimated by a condenser lens and directed to the sample through an oblique mirror. The choice was made to use a jewelry case 5 x 5 cm as the main body of the scope. Inside the case it was placed a metal chassis which the whole illumination system was assembled in. This chassis is screwed in the box and can easily be taken out by unscrewing it as shown in the picture (right.).

Illumination system in the chassis

Outside the box, over the lid, it was assembled the clips and the focusing mechanism to drive the lens plate, as depicted below.


 

Lens frame driver                                 Focusing wheel


 

The novelty of this model is that the lens plate is removable and can be stored inside the box while not in use what makes the transport inside the pocket perfectly possible without the risk of soiling the lenses. Inside the box, there is a small neodymium magnet to which the plate stays firmly adhered until its use is required for observation.

Lens in the holding plate.                    View of the inside

The lens system consists of a doublet lens having a 2.5 mm diameter upside down Stan-hope like plano-convex lens and a 1.0 mm diameter plano-convex lens as object lens. The doublet is mounted in a 15 x 25 mm steel plate.

Doublet sketch

An important note that should be added to this subject is the fact that the design of the doublet lens has been modified regarding to my earlier models. The resolution of this doublet appears to be superior to the previous lenses as the polishing technique has been perfected and allows one to obtain lenses with higher transparency and clarity.

The sketch below represents different views and parts of the pocket microscope.

3. Gallery of Images

The pictures being displayed below were captured using the objective lens described in this article and the setup from my previous paper published by Micscape Magazine on July 2006 – “Improving the Performance of the Single Lens Microscope”