A polymerizable unit that yields an electrochemically responsive polymer is anchored by polymerization within a polycaprolactone matrix to form an electroactive scaffold upon which cells can be cultured and in which the micro- and nano-topological features of the polycaprolactone matrix are preserved. A plurality of LED modules is thermally attached to the base of the heat sink. Typically, one data bit is embedded in each frame of an input stereo audio signal by modifying the frame to produce a modulated frame whose modulated saturation value matches a target value indicative of the data bit. The early-operation auxiliary switch is connected between the external connection terminals of the unit case, and the electromagnet has leads emerging directly from the unit case and connected to an external wiring. When the body is applied a force, the supporter moves along the slide rod to locate at a second position to adjust an angle between the body and the plane. The measuring structure can preferably be installed into and removed from an electron-beam welder and consists of a graphite slab from which a tungsten needle projects perpendicularly.