#1173: SweetSwitches

Today’s invention is a tennis racket with a piezoelectric crystal in the frame underlying each string.

When a tennis ball is struck (off-centre), the crystals detect the location and voltages applied to them are automatically adjusted in order to change the string tension at the impact point.

This instantly creates a local ‘sweet spot’ on the racket head, allowing greater control of the return shot.


  1. Hi there , I am quite interested by this invention. Looking more towards the money matter how would this invention approximately cost.

  2. Well that would depend on how well it worked and how many people wanted one. To develop something that worked effectively from scratch (assuming it’s not already patented by someone else) I reckon it might be done in a year-long project -say £150,000 -ish. The cost of the components could be as low at £30 per racket, so to allow for marketing costs and a hefty profit, the additional cost per racket would be ~£150…acceptable for professionals, if they were allowed to use it in competitions.

Comments are closed