Electronics like webcams, SBC devkits, gyroscopes, GPS transceivers, PID controllers, radios and timers can all be salvaged from America's e-waste. Sanctions controls on them are extraordinarily weak, the hardware itself is all extremely proliferate and low-risk to ship or take cross-border if you desired. The US is not the sole source of any of those components and preventing Russia from getting them would be unlikely to hamstring weapons development or production.