When you supply assets to Aave, you receive aTokens in return, which represent your share of the pool of assets being lent out to borrowers. These aTokens are ERC-20 tokens that you can freely transfer or exchange, just like any other token.

To withdraw your assets from Aave while they are being used for loans, you would need to first redeem your aTokens. When you redeem your aTokens, you will receive the underlying assets plus any accrued interest that has been earned on those assets.

The amount of underlying assets you receive when you redeem your aTokens will depend on the current exchange rate between the aTokens and the underlying assets. The exchange rate is dynamic and constantly changes based on the current supply and demand for the assets in the Aave pool.

To redeem your aTokens, you can do the following:

Go to the Aave protocol website: https://app.aave.com/ Connect your wallet to the Aave protocol by clicking on the "Connect Wallet" button in the top right corner of the page. Once you are connected, click on the "Withdraw" button for the asset you wish to withdraw. In the withdraw page, enter the amount of aTokens you wish to redeem, and click on "Withdraw". The underlying assets will be transferred to your wallet, minus any applicable fees. It's important to note that if the pool is fully utilized, there may not be enough liquidity to withdraw all of your assets at once. In this case, you may need to wait for borrowers to repay their loans and for the pool to become less utilized before you can withdraw your assets.

Additionally, keep in mind that withdrawing assets may trigger a taxable event, so make sure to consult with a tax professional before making any significant withdrawals.

If the utilization is 100%, you can't withdraw. This happened during the merge actually. Lenders were no longer able to withdraw because liquidity ran out for a few hours.