Back when this first started Meredith built a "prototype" in a couple of days which, to a layperson, would appear impressive. There was a function generator with an amplifier sending out ultrasound via an array of transmitters and about a meter away there was an array of receiving transducers that picked up the utlrasound. Then the output from those receiving transducers was rectified with a few diodes to get DC. In this demonstration she had a multimeter showing the voltage at the receiving side, and when she tweaked things just right, she received 5 volts on the receiving side. 5 volts is the standard voltage you'd use to charge a phone, or any other USB powered device, so it was reasoned that she had created a viable system that could charge phones wirelessly.

The problem is that any idiot can get 5 volts out of thin air. You can literally hang up a long bare wire and rectify ambient radio waves and get 5 volts. The trick is getting 5 volts and being able to supply significant amounts of current at the same time i.e. receiving useful amounts of _power_. Power = Volts x Amps and Meredith and her investors simply did not understand the importance of this equation that a freshman in engineering would understand. FOMO kicked in and they threw millions of dollars at her thinking it was going to be the next big thing.