There is an increased interest in renewable forms of energy across the world, with solar energy being one of the most promising forms. Over the last couple of years, we have developed the MET (MicroEquipment Technology). As an application of the MET, we selected the task of production of solar concentrators. Different types of solar concentrators with flat mirrors were developed and prototypes of these solar concentrators (approximately 1 m in diameter) were made. The proposed solar concentrators were developed on the basis of concentrators patented in Mexico, Spain, and USA. It may be possible to install these concentrators on horizontal roofs of buildings. However, installing them on agricultural fields has become the new trend. As an example, we propose to use them in the potato fields in Canada to obtain dual advantages such as for electrical energy generation and for the minimal loss of agricultural harvest. The second example was analyzed for bean fields, in Mexico. In this paper, we describe the main results in regard to microequipment development for solar concentrator production, several prototypes of solar concentrators with flat mirrors and their co-location and agricultural fields.

As machines become smaller, friction plays an increasingly important role in their performance. Although friction is a well-studied phenomenon, few studies have been performed on bushings and shafts with loads of a few tens of mN and dimensions of a few mm. In this work, the static friction coefficient is investigated for a miniature steel shaft rotating in bronze SAE 40 bushings. A new approach is presented to measure the static friction coefficient of a miniature bushing. The coefficient was evaluated without lubrication. It shows a linear dependence at loads higher than 152 mN and a nonlinear dependence at loads smaller than 152 mN.

This research demonstrates that Amontons’ laws, which state that the friction force is proportional to the (normal) applied load and is independent of the apparent contact area, begin to break down when the sliding solids have dimensions of several millimetres and loads of tens of millinewtons. The method used to test the hypothesis involved sliding a cylinder into another cylinder. The results indicated that the static friction coefficient as a function of the load exhibited hyperbolic behavior at low loads; the friction force was not proportional to the load. While the static friction coefficient as a function of the apparent contact area exhibited linear behavior, the friction force was dependent on the apparent contact area. The tests were conducted without lubrication and the materials used were steel on SAE 40 bronze and steel on polytetrafluroethylene.