Tag Archives: Ultraviolet

Polymer Bends with Light Useful for Artificial Muscles

A new form of self-assembling polymer film that bends and stretches when hit by light is pointing the way to a new family of functional materials. This flexing film is the first material to have been made by coaxing complex molecules to form large-scale, highly ordered three dimensional arrays—a discovery that could change the way that many active material are made, from artificial muscles to solar cells.

Figure 1: The light-responsive film is made up of polymer brushes (right) that have self-assembled into a two-layer, three-dimensional array (left).

Reproduced, with permission, from Ref. 1 © 2011 American Association for the Advancement of Science


The Skin is a Composite of 3 Layers

  • This diagram is from the copyright-free collection, The Sourcebook of Medical Illustration, edited by Peter Cull (Park Ridge, NJ: Parthenon, 1989).
  • Epidermis: outermost layer, mostly dead keratinized cells (stratified squamous epithelium). No blood vessels, gets nutrition from dermis. Dead cells slough off and are replaced by dividing cells in the stratum basale. Half life of skin cells about 35 days.
  • Dermis: contains blood vessels, nerves, sensory receptors for touch, pressure, hot, cold, pain. Also has hair follicles and sweat glands. All this is imbedded in fibrous connective tissue.