New-item "Illegal Characters in path" when I use a Variable that contains a here string

foreach ($Target in $TargetUSBs)
{
$LogPath= @"
$SourceUSB\$(((Get-CimInstance -ClassName Win32_volume)|where {$_.DriveType -eq "2" -and $_.DriveLetter -eq $Target}).SerialNumber)_
$(((Get-CimInstance -ClassName Win32_OperatingSystem).LocalDateTime).Year)$(((Get-CimInstance -ClassName Win32_OperatingSystem).LocalDateTime).Month)
$(((Get-CimInstance -ClassName Win32_OperatingSystem).LocalDateTime).Day)_$(((Get-CimInstance -ClassName Win32_OperatingSystem).LocalDateTime).Hour)
$(((Get-CimInstance -ClassName Win32_OperatingSystem).LocalDateTime).Minute)$(((Get-CimInstance -ClassName Win32_OperatingSystem).LocalDateTime).Second).txt
"@

    $LogPath = $LogPath.Replace("`n","").Trim()
    New-item -Path "$LogPath"
}

The Irony is when I copy and paste the contents of my variable and manually create a new-item -path and paste said contents it works but when I use the variable it does not... Brief summary of my goal I am taking a USB labelled ORIGINAL and obtaining the S/N of every USB plugged in at the time and creating separate log files for each with the title consisting of SERIALNUMBER_DATE_TIME.txt and these files are created in ORIGINAL USB

$LogPath contains for example the following: E:\Mattel\1949721369_2018912_93427.txt Yet when I use the Variable in New-item it indicates "Illegal characters in Path"

FYI $LogPath is a System.String not an object $TargetUSBs is filled with all USB drives plugged into the system

this method of using a variable for a path usually works fine for me only difference is the here-string I used this time around does this cause my problem? I hope not because I really don't want to fill that variable all on one line. New-Item's helpfiles shows <String[]> for -path parameter does this mean I have to use a string array? and if so how do I convert this to make this work?

Your problem is that Windows uses CRLF line endings (Unix only LF), so you still have CR chars in your path.

To fix this just use:

.Replace("`r`n","")

However you can easily simplify your code so you do not require the messy here-string or replace/trim...

By using a single Get-Date call you can format it to your desired output. This means you can just build the Path as a simple string and involves much less code:

foreach ($Target in $TargetUSBs)
{
    $SerialNumber = Get-CimInstance -ClassName Win32_volume | where {$_.DriveType -eq "2" -and $_.DriveLetter -eq $Target} | Select-Object -ExpandProperty SerialNumber
    $DateTime = Get-Date -Format "yyyyMd_Hms"

    New-item -Path "$SourceUSB\$SerialNumber_$DateTime.txt"
}