How i can store data code for LONG time 100-200y - Data Retention, Reliability, Lifetime, Flash

[gchini]

Tags:
Store, data, 100years, Memory, ROM, Endurance, Data Retention, Reliability, Lifetime, Flash, High temperature

Hi guys
I'm working on a research project in wich we want embeed sensors and logic, an ESP32, inside building's pillar surrended by concrete.
The esp32 collect data throught sensors, process them and send it to a sink using Bluetooth

Conditions:

• The device then can be never removed or replaced once is deployed (is in the concrete pillar)

• The device is externally powered by a electrical source (cables) then power is not a constraint.

• The data communication between sensors are made using Bluetooth. We have tested that we can transmit data from inside concrete to an exteranl sink that could be a phone.

• The device do not needs to store (write on memory) datas, the devices just reads process and sends enviromental datas. The deive can use READ ONLY MEMORY ROM to store the code no data store is needed.

Since the device CANNOT be removed my concern is to provide to the project a LONG LIFE EXPENTANCY (more then 100-200years), in particular I'm concerned about the fact that the data in Flash Memory could disappear after few years (10y) due to limitated Lifetime of flash memory in particular at relativly high temperature. If the data will disapper even the code stored in the flash disapper too and the sensor will fail to achieve the its job.

Question(s)

• There are kinds of memories (flash on not flash), even ROM (read only memory) that are suitable to store code/data (informations) for LONG (100-200years) time without fail with a size of 4MB or more?

• If yes where i can find them, i mean where i can buy? Wich producer ecc..?

• How i can integrate these memories in the ESP32? Can i replace them to replace the flash? Is it possible to do that?

• How i can program such memories? I mean how can i "flash" these kind of memory?

I thought that i can use a PROM: form wikipedia, "A typical PROM comes with all bits reading as "1". Burning a fuse bit during programming causes the bit to be read as "0" by "blowing" the fuses, which is an irreversible process." but i can't figure out where i can start.

[MicroController]

Flash memory should not be your only concern. ICs, capacitors, quartz crystals, solder joints, dielectrics and other electronics stuff are subject to aging and deterioration over time.

But as an idea regarding flash memory: Those chips are specified for many thousands of erase-write cycles, so if you'd, say, reprogram the flash once a year that would 'refresh' the data stored, restarting the specified data retention period each time.