I am a frequent traveller who utilises Changi Airport's automated immigration gates.
I have noticed that the fingerprint scanners are never cleaned. This is rather unhygienic and poses a health risk, especially since I have seen some passengers using their tongues or foreheads to moisten their fingers when their prints are not clear enough.
I have written to Changi Airport Group making a request for hand sanitisers to be placed at these gates, but to no avail.
I think it's important to take appropriate precautions to safeguard public health, rather than take action when it's too late.