elasticsearch + AngularJS - How to write a like query search ( not exact search )?

Question

I am trying to write a like query search (not exact search) but not able to.

Here is my anularJS code -

  angular.module('searchApp',[])
.controller('searchController', function ($scope,ejsResource) {

 $scope.searchSubmit = function() {
 var ejs = ejsResource('http://localhost:9200');

  var oQuery = ejs.QueryStringQuery();
  var client = ejs.Request()
            .indices('articles')
            .types('article');
  $scope.results = client.query(oQuery.query('art90' || '*')).doSearch().then(function (resp) { 
         $scope.searchResults = resp.hits;
         console.log($scope.searchResults);

    }, function (err) { 
        console.trace(err.message); 
    });
 };
});

The result, I am getting using the above is exact match only. I need like search ( e.g if i put art in search text then I should get my result back.). Any Help?

Thanks a lot in advance!!!!