He whose life is filled with continual discoveries is truly rich

Penkala's work covers some 80 inventions in the fields of mechanical engineering, chemistry, physics, aviation, etc., and are clear proof of the versatile and all encompassing technical talents of this man of an ever searching spirit.

Some of Slavoljub Penkala’s revolutionary inventions:

• mechanical pencil
• fountain pen with solid ink
• fountain pen and pencil clip
• hot water bottle and thermos flask
• rotary toothbrush
• ebonite (i.e. hard rubber, from which gramophone records used to be made)
• detergent for washing clothes
• pesticide
• systems for measuring liquid flow-through
• xylolite – preparation against parasites in railway sleepers
• brakes for railway carriages
• rail track system
• manometer
• dynamometer
• special microphones
• listening devices
  Penkala also produced calculations for a turbine rotor and helicopter rotor blades. By studying the flow of compressor-induced air currents around an air profile he discovered a new source of lift-off power.
  He also discovered a new medication against rheumatism, which he named Radium D. Francovka.
  
  He perfected the gramophone record stylus and other gramophone components, and invented a new material for gramophone records, anode batteries and the pocket torch.