Modern silicon design with mems sensors I suspect could do an awful lot with a gram.
Also, at this scale, not much can be done by hand, so you can make hundreds of them for not much more cost than doing one.
Also, at this scale, not much can be done by hand, so you can make hundreds of them for not much more cost than doing one.
In short, it’s a swarm of gram-scale probes and they work together to transmit.
e.g. you would need too much shielding and would go over the 1 gram restriction.