This book covers a broad area of STEM discipline, and is written as a textbook for biology, bioengineering, physical chemistry, electrical engineering, and computer science students. It includes muscle biomechanics, viscoelasticity, chemical kinetics, system analysis, analog and digital electronics, methods for interfacing the experimental apparatus to a computer, programming computers to carry out experiments, and mathematics needed for these operations. Emphasis is given to the essentials, so that a beginner can understand the content, yet the principles can be applied to a variety of advanced systems. This book also includes exercise questions for important equations to be verified. Trying to solve a problem by oneself fosters good thinking, creativity, and independence, which would be essential for exploration of science. You can start from any chapter based on your interest and need and jump around chapters as necessary.