Try the following, it should work for both mobile and desktop:
<div class="momentary">
<md-button> Momentary Button</md-button>
</div>
<script>
(function($scope) {
$('.momentary').on('touchstart mousedown', function(e) {
e.preventDefault(); //prevent default behavior
$scope.send({"payload": true});
});
$('.momentary').on('touchend mouseup', function(e) {
e.preventDefault(); //prevent default behavior
$scope.send({"payload": false});
});
})(scope);
</script>