Because adhesion and disk flatness must be maintained in varying environmental conditions, the bonding agent plays a critical role in the DVD. Typically, a hot-melt adhesive applied to both halves of the disk, the agent is normally cured by UV light. This process, however, can take hours for the bond to reach final strength.
Imation Corp., Menomonie, Wisconsin, has developed a pressure-sensitive adhesive for DVDs that does not need lengthy curing. The product, called SP-5, is applied to the substrate surfaces as a liquid and when briefly irradiated with UV becomes a high-tack solid glue. Once the disks are mated, no further curing is needed, thus reducing stresses in the substrate which could affect optical properties.
To compare, a DVD has a 0.74-micron track spacing and 0.4-micron minimum pit length against 1.6 microns and 0.83 microns for a CD. In addition, the DVD player's laser can still read the larger pits of a CD, thus giving the desired backwards compatibility.
Robots that walk have come a long way from simple barebones walking machines or pairs of legs without an upper body and head. Much of the research these days focuses on making more humanoid robots. But they are not all created equal.
The IEEE Computer Society has named the top 10 trends for 2014. You can expect the convergence of cloud computing and mobile devices, advances in health care data and devices, as well as privacy issues in social media to make the headlines. And 3D printing came out of nowhere to make a big splash.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.